I wouldn't worry too much about PH either way, unless you want to breed fish have proven very adaptable - unless your water is really extreme on one end or the other.
It seems you already mentioned two fish you like - Angels and Gouramis, so only you can decide which you prefer.
Angels are new world cichlids, so once they mature (breeding age) they will form Monogomous couples. These pairs will then begin to act aggressively toward the others. You can start with about 4 of them, but eventually when a pair forms you'll be removing the others - two fill a 29 gallon.
They can go with any of the more peaceful fish that are not small enough for them to eat - you're options are wide open.