my advice is to change your plan and make your first tank a freshwater one (fw is easier to care for than sw; also, sw sucks; the best fishes are freshwater). if you do this then you could stock it with one of each of the following fishes most of which you can find at massive agression and aquascape (be sure to get fishes that meet the size requirements listed respectively):
1. high-back peruvian black rhombeus piranha (2"-4" in length)
2. african tigerfish (5"-7")
3. red throat sanchezie piranha (2-4")
4. manuelli piranha (2-3")
5. adonis pleco (5-7")
the tank size must be 300 to 400 gallons (not larger than 400 and not smaller than 300 (small tanks are for wimps and the fish you will be stocking the tank with need this much space because they are extremely agressive and territorial). go buy a cattle water stock tank from the nearest tractor or farm supply shop. you might be able to find a rubbermaid 300 gallons tank at target or walmart.
for filtration get an Fluval fx5 filter and stock it with four packages of biorings and two packages of pre-filter media (do not buy nor use olishing pads).
get small fine natural dark gravel, enough to cover 1-2" of the tank.
get two 300watt submersible heaters.
get some cucumber for the pleco. and pellets and raw white fish for the pleco and other fishes.
get a "mag power head" that pumps 500gallons or more per hour.
get seven, long, 18" or longer, bubble pads and enough air filters to power these bubble pads.
buy fifty feeder fish to put in your tank to cycle it. read about how to "cycle a tank". buy biospira to quicken the process.
once the tank is cycled, add your amazing fishes. you should also use large rocks to create one hiding space for each fish.
If you do as I said you will probably have the most amazing first tank in the history of fishkeeping.