What Led fixture to get

[Lampshade]

Check out:
http://www.manhattanreefs.com/lighting
In the LED section he has par values over area coverage. LED PAR values are a mess right now while people argue about "good PAR" vs. "bad PAR" but gives you a good idea of the coverage of the fixtures

Overall it comes down to what you want to spend. You can make anything work from a used 250W halide for $100 to a $800 radion fixture.