Hi RonW,
The closest lists to you would be the Monroe Township/Newark, NJ area list here and the list for the Trenton/Philadelphia/Wilmington region here.
Outside of these I took a look at the area around Red Bank, NJ (within about 30 miles) and the better options or possibilities that I could see and the brands I would consider with each on a “mattress by mattress” basis (making sure you can find out the specifics of what is inside any mattress you are considering) would be …
http://redbanksleepshoppe.com/ Red Bank, NJ. Englander (make sure they can provide you with the specs).
http://monmouthmattress.com/ Red Bank, NJ. OMI (premium price latex mattresses), Paramount (the specs may not always be available).
http://www.waltssleepshop.com/ Middletown, NJ. San-O-Pedic. This is their house brand made by Therapedic/Bedding Industries of America so it should be possible to get the specs of these mattresses (Bedding Industries of America tends to be more transparent about the mattresses they manufacture) but there are no details about their price range or the type of mattresses.
http://www.thebedroomgalleries.com/ Howell, NJ. Retailer who carries a range of mattresses including latex in a range of budgets and brands including WJ Southard and Classic Brands.
http://www.mrmattressusa.com/ Toms River, Manahawkin, NJ. Talked with Eddie and he knows his stuff. Carries some Gold Bond two sided mattresses which would be worth considering here. Very knowledgeable about mattress materials and specs but doesn’t carry any latex.
As always … I would call first to talk with any retailer you are planning to visit along the lines of this article to make sure they are willing to provide the information you need to make an informed choice and to get a general sense of their level of knowledge and service.
Phoenix