Don't mix them with your current fish. They are much more sensitive then regular uaru. The fish you currently have like hard water and Uaru fernandezyepezi require lower ph's and softer water. If you put them in with your current fish they will get picked on, stress and break out in ick and die or just get picked to death.
You should definately pass unless you can give them there own tank and meet there water requirements. otherwise you are just going to waste a bunch of money.