To be honest, i'd reduce some of the rocks in there. I'd say that's almost setup for mbuna. Strawberry peacock/firefish/dragonsblood can be nasty for peacocks since it is beleived they have mbuna in them aswell to attain the colour. However I'd safely say you could try most of the more aggro peacocks in there with no trouble. maybe a nice hap ahli. Reallly though you should be using a 4 foot tank for peacocks of possible. Have you considered going Mbuna? you are pretty much ready to go if you do, and the peacock you have may well end up mixing just fine.