jetmonkey - I love the bottomfeeders, too! I have 9 Corydoras in my 55 gallon: 2 Panda, 2 Shultz, 2 Albino, 2 Bronze, and one Peppered. I've been thinking about getting a zebra pleco, but they're so expensive! Oh, I cover my tanks with a simple pane of glass. I measure around the rim inside the top frame of the tank and order a piece of single-strength glass from A&M Glass. My 135-gallon doesn't have a full top, but the only jumper I've had was a shrimp! (My dog ran and woke me up until I got out of bed and rescued it!)
missi - I would suggest nosing around the classifieds for a bigger tank. Tanks will pop up down here once in awhile, but you'll usually find something in the Baltimore Sun and Washington Post. Also check the Pennysaver. If you buy one, fill it with plain tap water and let it sit overnight on some newspaper so you can check for leaks! I would advise against using a 20-gallon for your first saltwater tank; I have to do a water change on mine every other day! Shoot for something the size of a 40-gallon breeder or a 55.