Definately no to the GT, they require a minimum of a 55g tank just for themselves with maybe some fast dithers, males can reach 12" and are extremely aggressive fish.
The BP, I have no personal experience with, but I would still think they require a larger tank than 30g.
If your looking for cichlids for that size tank, your better off looking at the dwarf species, like bolivian rams (not german blue, they require a higher temp than the rainbows could live at), keyholes cichlids, curviceps, apistogramma sp., Hounduron Red Points, Thorichthys species - Ellioti, Aureus, although not Firemouths (Meeki) as they are more aggressive than other in the Thorichthys genus.
