You're correct, water quality is of utmost importance too.
Maneating guppy: None of those lights will work with your tank. The first one would fit your tank, but would not be enough for any corals or clams. Yes it is expensive, but if you want to keep these beautiful creatures it is necessary. It is not possible to do cheaply.
Just be prepared, to keep corals and clams you are looking at a starting price of probaby $300-400 for a somewhat decent lighting setup.
Careful about LFS advice...most are not too knowlegable about reefkeeping, and will just reccomend what they have to selll you. (And if they have the correct stuff, it will likely be MUCH more expensive than online)