For medium light, you want atleast 2 watts per gallon.
I suggest getting the
2x65w Coralife fixture, which would give you about 2.4wpg. That fixture is about $10 more than a
triple fluorescent fixture at Drs. Foster and Smith and well worth the extra money.
Hellolights.com usually has the fixture cheaper than the Drs, but their site says call to preorder, so I guess they dont have any right now.
You should get alot of stem plants with that light. Plants like Bacopa, Rotala, Ludwigia, Pennywort, Hornwort, and Anacharis are good. You will also be able to grow Swords, Vals, and some foreground plants like Dwarf Sag and Echinodorus tenellus.
Plain gravel is fine. You might want to pick up some
Flourish too.
That's about all you'll need (lights, plants, Flourish).