keep an eye on those Managuense fish, Rom.
in general, it isn't good to mix cichlids of different regions since S.A. and Africans each take diff pH, diet, salinity, and water hardness....and of course, temperment.
i only got a 55gal setup now...just don't have the time.
African Cichlids.....
5-stripe Frontosa male
Rusty Cichlid [Iodotropheus Sprengerae]
a few yellow Labs [Labidochromis Caeruleus]
female Hap Comressiceps
pair of Regal Peacocks
white top afra [don't get big but nasty lil' guys.....had 2 but had to give up on 1 of them cuz they each owned half of the 55]
Lamp. Tretocephalus
Syn. Decorus [one of my prized fish cuz i've had it for over 15yrs...about 14in]
Syn Lace [aka Syn. Budgeti]....sentimental to it cuz it is my oldest fish....about 12 inches....enjoys inverting himself in some african bogroot.]
odd fish include,
a striped raphael which hides alot....probably the most noctural catfish u can get next to it's cousin, the spotted raphael.
also have some dither fish....a large group of Giant Danios work really well as darter fish for an African setup]
got 2 Rhino Plecos in it too and hold their own quite well.....i've also used Gibbiceps, Rusty, Royal in the past with great results.
plenty of filtration/circulation too....1 powerhead, (2) 403 Fluvals, (1) 303 Fluval
sorry, don't have a camera
btw, i think u mentioned plants with ur african cichlids or S.A.....hard to keep plants with Africans since they either dig, or eat them like mbuna's do, or just don't thrive in a high pH with such a salinity and water hardness....the only real indigeneous variety would be a Val species, eg corkscrew.....the plant i stay with when it comes to Africans is Java Fern....hearty plant and grows on bog root....the plant is actually poisonious but won't hurt the fish cuz they simply spit it out and learn.
for S.A. cichlids, it is hard to keep plants because of the digging....i tend to recommend to people something like Amazon Swords simply because they have a broad leaf and thick stem....also try planting them outta harms way like the corners....otherwise, like with an African tank, plastic plants is the most cost-efficient way to go.
regarding Stingrays, keep an eye on ur aggressive fish with them....a rays vulnerable spot is the eyes so i tend to tell people not to mix them with S.A.'s....Arowana make good tank mates with them though cuz of the 2 different levels at which they swim [blue arowana is the prettiest but most expensive...gold arowana is nice too but endangered so off the market for quite some time now........also used Clown Knifes [Royal Clown Knifes are the prettiest].....black ghosts work well too since they love soft acidic water also....black worms and grass shrimp are a nice treat for Rays.
ur buddy probably has a Motoro Stingray judging from the size u mentioned.....Hysterix is the next size down....and T-Cup is the smaller of the 3 species u tend to find in stores.
btw, i've worked at a pet store parttime since '91