Actually, I'm not sure what is going on, but Virgin Mobile only has one coverage map. While it has a link from each phone, they are go to the same coverage link. As such, I'm not sure how you are getting different results.
Regardless, if you aren't getting 3G now, unless there is an actual hardware problem with the Rise (if you take it to a place marked 3G on the coverage map, do you get 3G?), you aren't going to get 3G with any other Virgin phone.
One thought: if you aren't looking at the Virgin Mobile coverage map and, instead, are searching for coverage for the Evo 3D, the results will not be valid. The Evo 3D is the Sprint name of the phone, so it would give you Sprint coverage maps. If it shows coverage for the Evo 3D in your area, it is likely due to a roaming or similar agreement and not from a Sprint tower -- and Virgin Mobile only has coverage from Sprint towers.