Do you need a short top tube? Specialized makes a nice bike with a short top tube. For me it wasn't comfortable but others like them. The Myka is a cost friendly full suspension that has 4 or 5" of travel (I think). I love my full suspension and it has made mountain biking more fun. A trail bike is going to be a bit heavy (mine is about 27 lbs) but is probably going to be what is in your budget. I don't notice the weight, just the fun!
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan