Sounds like your getting some good info here. Fronts tend to get very large, slow growing and peaceful. They are wimpy when housed with other species so extreme care must be given if they are not kept by themselves.
Typical frontosa tank : six foot or larger, 6 to 8 frontosa (1 or 2 M/ rest females), sand substrate with rocks and caves, Higher PH's (7.5 and above) and hard water.
In bigger cities they are more common but still pricey compared to other cichlids, in more rural or isolated areas they are more rare and command very high pricing. Several good breeders online are doing shipping and offer a more reasonable option.
A 55 gallon tank would make a perfect grow out tank for a group of juvie frontosa but if you get them keep in mind in 6 months they will have to have to be moved to a six foot or larger tank due to size of fish and more important their aggression to each other (even though they are wimpy to other fish they are not wimpy to each other and will squabble and fight bad in a small tank.) You can often save hundreds of dollars by purchasing a used six foot tank out of the classifieds in your local area.
Burundi type frontosa are most common and both male and female get a huge hump on the forehead . Their colors are still nice, with bluish white stripes. Typical price in a shop : 20-30 dollars each fish. Price from online breeder : 10 each plus shipping
Tanzanian and Zaire types have a much smaller hump but are very blue compared to the burundi fronts. These are much more expensive and sought after compared to burundi but can be purchased online from breeders for more reasonable pricing. I went with Tanzanian (mpimbwe strain) and love em, they were online purchase and i got 10 of them for 120 dollars including shipping (they even tossed in two extra for me since i ordered smaller sized juvies under a inch that were onsale). Most shops dont carry them and when they do they can be super expensive, best to order from reputable breeder.