Anything big enough not to fit in their mouth, but not too aggressive as to rip that said mouth from their head. Do you already have the green? If so, pics please. I have a red, but love greens as well. Don't see too many of them.
oscars should work out fine, they are not particularly aggressive, as for the GT, it should be ok as long as the individual fish is not especially aggressive
Cool about the Oscar. I really love the colours on the wild type.
GT, IDK guess I will have to get them and try. There is only 2 at the LFS at the moment so I will get both and see which one is less agro, hope it's a male
Yeah, I see no problems with the two of those either. They both have that similar temperment across the scale. Nice little guys. You'll have to keep updates on them as they grow.