Is it pre-drilled or standard?
If it's pre drilled, I would save money and not buy a wet dry. Use a 20 gallon tank, preferably acrylic to eliminate possible leakage. Stick filter floss or filter pad on top of a mess of bio-balls in the overflow.
Since your starting from scratch, I would deffinately opt for a very strong pump with a return manifold plumbed in with 4 or 5 returns. I hate my powerheads! I use a Mag 7 pump on my 72 gallon which pumps 400+ gallons per hour at 5 feet of head, which is what you will be running at. I have two returns, but I still have to use powerheads to get enough flow. If I were you I would get a Mag 9 or a quiet one with a GPH rating of at least 500 at 5 feet of head...maybe more! Your tank will look much nicer without those ugly power heads. Plumbing a multiple return manifold can be daunting to a beginner, but do look into it; the couple of hours of effort will make your tank much better in the future.
Don't skimp on a pump and get a Rio! Stick with Mag pumps or Quiet Ones.
Get a decent skimmer too!
In short, if there are three things you should not skimp on in a reef tank, they are circulation (large high quality pump), skimming (no HOT), temperature stability (no cheap heaters...spend the extra $30 on a good quality heater.
Good luck