Well with a friend who owns a pet store and being willing to order online... that opens you up to A LOT of options
Knowing a few more details about what your looking for can help narrow things down a ton. Which your giving us...
So it sounds like you would be more interested in having a larger group of semi docile small to medium (4" ~ 10") growing Cichlids than just a couple large heavy hitters... that makes a big difference...
I have a 6' 125 Gal with a large group of Geophagus steindachneri (Red Hump Geos) that are very entertaining. There are a few other species of Geos that stay relatively small (4" ~ 7"), are very showy, are active, stay docile and interact well as a group... Red/Orange head Tapajos are a very common one...
Blue Acaras are a nice looking fairly showy more docile fish that would work well with Geos...
I have a pair of Elliot's Cichlids (very similar to Firemouthes) with my Geos and they work well. The Elliot's have less of a red throat than FMs but have a lot more blue/green shine on their body. Elliot's or FMs would work well with the above...
Convicts/Honduran Red Points stay small but get a bit aggressive, I'd avoid anything that would be more aggressive...
If you have dense rock/wood formations you may consider getting some Apistos to lurk in them. Males can be very pretty and are intelligent, fast darty fish. The females I've kept weren't so good at avoiding predation, but the adult males were... They will definately need cover to hide from larger fish though...
A larger growing fish that commonly stays fairly docile is the Severum... I would avoid a pair of them though to keep aggression down...
Lots of non Cichlid options could go with these... as well as the suggestions offered by Andy above...