I really don't see why you can't keep a peacock in that tank.
The fish already in there might object, but the peacock would be very happy to have some nice little meals in there.
And that might solve another problem:
Seriously, though, you listed seven species of shoaling fish in a 29-gallon tank. Assuming a minimum of 3 each (which is low: most of those fish would be happier in groups of five or more), you have 21 fish in that tank. I don't think you should add a peacock or any other fish to the tank. The flying foxes, depending on which species they are, will easily reach 4-6", and are very, very active fish that like clean, well oxygenated water. A 29-gallon is kind of small for them, long term. Your guppies, also, are going to reproduce and crowd that tank.
Might be time to consider a bigger tank. :-D