Can't help you with stock available to you but as far as price, my LFS just got a large shipment of 4" flowerhorns in and they have them up for $75-90 each. They are good looking specimens though.
I'm sure that there are breeders on the East Coast that can help you out with one or importers. Have you tried Craigslist or just local facebook pages?
If you're not too concerned about price, you can also have one shipped to you from an online dealer.
For sure i would go with dwarf pike cichlids (Crenicichla compressiceps). These things attack anything that hits the water with incredible speed. I breed my own guppies but have dropped in large comets every once in a LOOONG blue moon for my oscars and these guys have taken on a golfish their size. They are incredible. In a 40b you could probably get away with 4 of them as they max out at like 4 inches.
many of the species in the Amatlitlania, Aequidens, and Andinoacara genus' have smaller species that would bode well in a 40 breeder as a pair or centerpoint to a small community...
I've been researching the same thing myself for my 40 breeder and those are the genus' I have my eyes set on ATM