Instead, I would setup the 55, and then cycle it fishlessly (there are several threads here outlining the process, with links for specifics). This will prevent your fish from being exposed to toxic levels of ammonia and nitrite. You can use some gravel and filter media from your existing tank to speed up the process.
For other fish selections: there are rams that are hardy, and ones that aren't. I think the Bolivians are considered hardy, and the German ones more sensitive. They are a lovely addition, and can be good community fish.
Gouramies--it depends on the fish. I have color morph three spots (sold as gold and platinum) that are shy and quiet. I had blue dwarves that were little buggers, and ones that were very mellow. It just depends on the fish.
I would avoid the balas. They get very large, need to be in a school, and tend to be very skittish, ramming into the glass when startled. Not a good choice for a 55.