Bolivian rams, German Blue rams and keyholes would all be fine in that size tank and with those tankmates.
All prefer a range of ph from 6.6 - 7.4, but higher is possible - my rams and others on the forum are in higher upto 7.8. Although care should be taken when acclimatizing. I imagine most from your area will be accustomed to the local water, so really not a problem.
They all require very good water conditions, ie, no ammonia, nitrIte and nitrAtes as low as possible, preferably under 20ppm, again depends on your tap water how low you can keep it, but I do twice weekly water changes to keep mine low.
If it were me, I would get 4/5 of each, then allow them to pair off and return the others, however if you dont want a pair, then start with 2 and see how they get on. Most rams are peaceful and only get a little grumpy with their own kind, unless they are spawning and most of the aggression as such is complete bluff, they dont do each other any damage so its not normally something to worry about.
Provide them with plenty of plants (fake/real) and caves to claim as their own and you should be ok.