You have the right idea, first of all. The more water, the more stable- and shrimp are more sensitive than fish to keep. You will have to measure gh/kh and TDS in addition to the "fish water" tests.
If you want crystals (crs/cbs), OEBT, BTOE or TB, you are looking for a ph of closer to 6, which can be done by a buffering substrate with a lower than room temp.
If you want neos, your ph 7+ should be fine with room temp.
If you want Sulawesi, you are looking at 8+ for ph and a temp of 80+
Just about any snails are fine with shrimp, as long as they match the temp desired. Assassin snails are teh exception. They do a great job of getting rid of snail infestations, but also can get rid of some of your shrimp, too.