They really do do their job! The bristlenose will eat all the algae, but creates a lot of waste. Ottos are very sensitive, and need a mature tank, they are often in poor condition in lfs, so not many people have much luck with them, hopefully somebody else can point you to a good source.
An alternative would be shrimps eg amano shrimps, they are algae eaters, no strain on the bioload of a small tank, and fun to watch too! Should be ok with rams, but might be worth having some shrimp-sized hidey holes just in case.
I like rams but for some reason never got any... I have cockatoo dwarfs cichlids, which are smaller, and you keep 1 male to 2 females.
Silvertip tetras are great fish to watch, and hugely underrated IMHO! Wait til the evening and they start playing, chasing each other around. Also look stunning with the right light as their tips really glow.
HTH