based on the list you provided, it really depends on tank size, because just about all of those options will require very different sized tanks... if you have a small tank (55 or under), i'd stick with a sanchezi or even a small rhom if you can upgrade later, i'd recommend a 75 gallon tank for the elong, and at least a 75 gallon, preferably larger, for a group of pygos.
if tank size is not an issue, i'd go with either a rhom or a group of natts depending on whether you want a solo fish or a group. i like groups of pygos, but they require a lot more room, a lot more maintenance, and a lot more food, so that's always something to think about.
if tank size is not an issue, i'd go with either a rhom or a group of natts depending on whether you want a solo fish or a group. i like groups of pygos, but they require a lot more room, a lot more maintenance, and a lot more food, so that's always something to think about.