Hi Mook3223,
While there are no factory direct manufacturers within 50 miles of you that I know of (which I always find strange since I would think the Baltimore - DC corridor would have more choices) … there are certainly choices which are better than others and IMO better value than the ones you mentioned. A side to side “split” may be a good option for you because of your different preferences (where each side can be custom made for each of you but without the excessive cost of the myside mattress).
Some of your better options that are within 60 miles of you include …
http://americanfoamcenter.com/ Fairfax, VA., Hagerstown, MD. They are a foam store but are also a local factory direct mattress manufacturer. I talked with Robert (who is the owner) and was very impressed. It’s clear that he “knows his stuff” about foam. He has been making mattresses for 50 years and is the kind of person that will give you accurate information. He also has a “showroom” (of sorts) where different materials and layers can be tested. He uses high quality materials like Latex (Dunlop and Talalay), high quality polyfoam up to 2.8 lbs (true HR foam) and memory foam from a quality American supplier. They are a high quality and good value choice, especially for the area, and I would certainly suggest that anyone in the DC area include them in their research. Make sure you call first because Robert is the person there with the knowledge.
(UPDATE 6/17/17: Forum member reports that AFC no longer sells to public.)
http://winndom.com/retailers/ Wholesale manufacturer who sells through local retail outlets. Their retail store finder has a list of outlets. I have talked with them and I know they work closely with their retailers and provide good quality and value. In particular though … I would talk with Michelle at http://www.bedcraftersbymichelle.com/ in Williamsburg, VA who works very closely with them and is exceptionally knowledgeable and helpful about all their mattresses and mattress materials and construction in general and custom builds every Winndom mattress she sells. She is a great resource for Winndom regardless of which retailer you are dealing with.
http://www.urbanmattress.com/ Vienna, VA. Retail direct outlet for their own house brand (Urban organics latex mattresses), along with a range of mattresses made by Sherwood, Suite Sleep, and VI Springs (ultra premium). Good people who have always been knowledgeable and open about their mattresses when I have talked with them. Some good value.
http://www.roomandboard.com/ Washington, DC. Retail direct outlet for mattresses made by Restwell Mattress. They carry a range of mattresses including latex, latex hybrids, and memory foam including some which can be customized side to side. Check foam densities for memory foam and polyfoam carefully here to make sure they are good quality.
http://www.savvyrestnaturalbedroom.com Factory direct manufacturer in Vienna, VA and Rockville, MD.
http://www.themattressorganic.com/ Savvy Rest direct outlet in Columbia, MD. They make or carry many options of different high quality “choose your own layering” mattresses with zip covers made of both Dunlop and Talalay latex and which include side to side splits. They are more costly than other very similar mattresses however that are available online or from other manufacturers but are a good place to test various latex layering schemes.
Some retail outlets near you that carry some “alternative” brands that may have better value than most national brands or typical chain stores but don’t offer side to side splits (to my knowledge) include …
http://www.healthyback.com/ Retailer in Bethesda, Rockville, MD and Alexandria, Vienna, Fairfax, VA. Carries Pure Talalay Bliss which are a high quality talalay latex mattress line which is better value than most national brands but are more than latex mattresses made by most local manufacturers.
http://mattressfame.com/ Retailer in Rockville, MD. They carry several brands which may have better materials, quality, and value including Therapedic, Eclipse, and Eastman House, Englander, Pure latex bliss. They carry latex, latex hybrids and other options such as gel memory foam that may have some better value and are open to supplying the specs of their mattresses (to the degree that the information from their manufacturers allow it) so customers can make more meaningful comparisons.
http://www.abbafutons.com/ Gaithersburg, MD Foam and Upholstery shop that also sells some mattresses and futons. Talked with him and he knows his foam. Carries poly and memory foam but no latex. Sells Otis futons and basic foam mattresses.
http://www.mattresstraditions.com/ Retail Outlet in Falls Church, VA. They carry several brands but their best value is probably Classic Brands (a smaller national brand) and Winndom (a regional brand). They also carry Natura which makes a side to side split but I don’t know if they carry it and even if they did Natura is not great value. Winndom will often work with their local retailers to make custom variations of their mattresses so a side to side split may well be possible.
Shop Affordable Home Furnishings & Home Goods - IKEA Baltimore. Carries a Dunlop latex (85% natural) over pocket coil mattress and an all Dunlop (also 85% natural) latex mattress. Both of these would be quite firm however they would make a good base for an additional softer talalay latex topper. Also see post #3 here.
http://www.mattressstoremd.com/ Annapolis, Kent Island, MD. Has a Serta all latex mattress made to their specs (with an inch of poly on the bottom). Retonic latex hybrids (2" and 4" latex) and all latex (with 1.5" poly on top). good people locally owned. Mostly mainstream major brand mattresses.
http://magicmattress.com/ Westminster, Eldersburg, MD. Paramount, Restonic, and Symbol. Long term retailer with good factory connections and said he would get foam specs if asked (and make sure you ask).
http://www.americanmattressinc.com/ Crofton. Carry Restonic and Symbol. They also carry Body Tech mattresses although I would make sure you check the foam quality/density specs with these because it’s likely that they use lower quality materials.
http://www.discountmattressoutletonline.com/ Laurel, MD. Therapedic gel and latex hybrids. Said he would provide specs for all his mattresses.
http://www.mtairymattress.com/ Mt Airy, MD Carries Restonic Gel (but but no latex). Have a good relationship with the Restonic factory so will get foam specs.
There are some local manufacturers a little further away towards the Wilmington/ Philadelphia that may also be well worth a phone call or a visit and they are included in the list in post #4 here.
So while there isn’t a single outlet that has the best of all worlds, (distance, quality, value, service) at least you have some better choices … especially if you are willing to do a little driving.
Hope this helps
Phoenix