I would look into apsitogrammas and rams and see if you like them. I would say the firemouths would not work in a 29 g, IMO. I had my boyfriend's convict in my tank while he grew out, and he ended up tasting my tetras... so I'm not sure if that would work. Maybe with a more wide-bodied tetra, but I'm still not sure if it would work.
I have rams and apistos, and love them. They're really versatile if you want a community tank. I have cories, tetras, and a pleco in with mine, and I love my tank! There are a lot of cool varieties of apistos with a lot of awesome colors that bring vibrance to a tank.