Hi,
What about a pair of GT, a pair of Firemouth and a pair of Nics, or Jack Dempseys?
He started with 6 young fish of each species
Those GTs and Nics look awesome.
I wouldn't keep a long firemouth tho. Little guy looks lonely. Thorichthys should be kept in groups. Also, I'd look for something like a Thorichthys maculipinnis, much better looking than meeki IMHO, and I'd keep ~7 of them. Also, they need a fine sand substrate.
I don't think anyone can definitively say whether your list would work. If your tank is 125 gallons or more, it could work out, but be ready to rehome if needed. If it does work it will be a very fun and interesting tank, that's for sure.