Hi niswave,
The Sleep Options has 2" of 20 ILD Dunlop latex over 6" of firm, 40 ILD polyfoam so as you mentioned this would be a fairly firm mattress (because of the higher ILD of the base and because the comfort layer is only 2" of Dunlop). When I went to look, the online price at Sleepy’s for the mattress only is $1229 and for the set is $1475.99. At Walmart, the online price for the mattress only is $729 and the price for the set is $1039 so the difference between them is substantial.
This is unfortunately true but there are some good options available to you within reasonable driving distance. Most of them are listed in post #4 here. The closest factory direct is …
http://www.raitensleep.net/ is a factory direct manufacturer in Monticello and is owned by a husband and wife team that build some high quality and value mattresses using mostly innersprings and high quality polyfoam (2.6 - 2.8 lb density with 1.5 lb in the quilting as necessary). they will also make a latex mattress to order although they don’t carry them on their floor.
Other than them, there are others within a distance of about 100 miles or so that include some high quality and value factory direct manufacturers in CT if the drive is worth it for you to actually lie on a mattress that you purchase. A list of these is in post #2 here. I think a call to Restopedic in particular may be worthwhile in terms of value.
The link I gave also includes some retail outlets that may offer some better options than some other choices in the area but I personally would go with the factory direct outlets that are within reasonable driving distance or an online purchase unless a call to these turns up a mattress (where details about all the layers are provided) at a price that just can’t be resisted 
SleepEz uses high quality Talalay and Dunlop latex both of which have no harmful outgassing (have been indpendently tested). Latex though can have a slight odor when it is new (either a vanilla type of odor or a rubber type of odor) but neither contain harmful VOC’s even for a child or infant.
Their Talalay latex comes from either Radium or Latex International and they choose the source that they believe is currently offering the best quality. Radium and LI are usually very comparable but there are times when one may provide better quality than another and they (and other manufacturers) look at this before deciding which is the “default” they would include in their mattress although either can be chosen by request. I believe their current “default” is Radium.
Their 8" 3 layer default option would be slightly softer than the Sleep Options both with Talalay and Dunlop “standard” choices (the sleep options uses a firmer polyfoam as their base layer and has no transition layer which for most people would create a firmer feeling mattress).
While I personally prefer a slatted base for added ventilation and breathability, latex is breathable enough through the ticking and foam itself that a solid foundation would generally not present a significant problem in most cases and there are some people who actually prefer this. It would depend to some degree on the sleeping environment and humidity. The upholstery in your bed may also improve the breathability slightly vs just sitting on wood alone.
Hope this helps
Phoenix