You said it's a 120 gallon? Not sure about garras (I think they have special requirements like fast flowing current or something, don't quote me) but the other two would be perfectly fine. Personally, I love my SAE's in my 125 but they occupy more of the mid level of the tank. Great algae eaters and they look really cool IMO.
Anyways, I would reccommend starting out with a colony of shrimp like Red Cherries, or another Neocardinia species, that can reproduce fast and fill up your tank. Ghost shrimp will get lost in a 120g unless you have a bunch. Another benefit of Red Cherries is that if you get a good size colony going they'll reproduce fast enough in case some are eaten by the fish.
Larger cories would be a great idea plant wise, but they'd probobly eat shrimp. The pygmy cories would get lost unless you had a giant school, I think something larger would be much better. Not neccessarily one of the giant 4" cories like the emeralds, but something like peppered or agasszi corys would work well.
Anyways, I would reccommend starting out with a colony of shrimp like Red Cherries, or another Neocardinia species, that can reproduce fast and fill up your tank. Ghost shrimp will get lost in a 120g unless you have a bunch. Another benefit of Red Cherries is that if you get a good size colony going they'll reproduce fast enough in case some are eaten by the fish.
Larger cories would be a great idea plant wise, but they'd probobly eat shrimp. The pygmy cories would get lost unless you had a giant school, I think something larger would be much better. Not neccessarily one of the giant 4" cories like the emeralds, but something like peppered or agasszi corys would work well.