Hi djarchow,
Some of the better options and possibilities I’m aware of in the Cedar Rapids / Dubuque area are listed in post #4 here and for the area in and around La Crosse, WI are listed in post #3 here just in case any of these are closer to you.
Most people wouldn’t notice much if any difference with an ILD difference of 2 or 3 (and the ILD variance of a latex layer is in that range anyway) but if a mattress is a little too firm you can always add a topper but if a mattress is too soft then you would need to remove or replace layers rather than adding to them. At your weight, and unless your testing indicated otherwise, I would tend to lean towards a little firmer rather than a little softer.
Phoenix