Buying a 55 gallon aquarium, want to set up a reef tank?

I am buying a 55 gallon aquarium on Craigslist with a 250W heater hood+lights and a Aquaclear 50 filter. I want to set up a saltwater reef aquarium (I have a decent amount of experience, in one of my tanks I have a 6" Gold Gourami, 5" long marble veil angelfish (about 8-9 inches tall), and a 4" albino angelfish (about 6-7 inches tall) as well as an oto catfish and 2 cory catfish, cardinal tetra and two zebra tetras . I test the water daily (even though I'm a bit overstocked), 0ppm ammonia 0ppm nitrite, 6ppm nitrate, I make up for the overstocked tank by using a Fluval 205 filter as well as a crappy Top Fin 20 gallon filter the tank came with. I also have another tank with 0ppm ammonia, 0ppm nitrite, but 30 ppm nitrate (algae problem), it has a Marineland filter rated for 55gallons on it. I think I have enough experience to move on to saltwater, but I want to start big, my question is will the Aquaclear 50 as well as another Fluval 205 (on sale in P3tsm@rt **not sure about the rule regarding store names on answers** for $60) be enough to filter a 55 gallon reef tank (Fluval is rated for 40, the Aquaclear is rated for 50 though it's probably only good for 25)? And will a 250W heater be enough to heat it? And finally, does anyone have any advice on what to stock a 55 gallon reef tank with, in terms of fish? And species of coral? As colorful and beautiful as possible. What else do I need in terms of equipment or anything (besides salt and live rock, obviously) for a salt water tank?