For what you need now, really, any of those NLE’s will be fine. Heck, throw Avid Liquid into the mix, it might prove to be a better buy simply cause it is a fully integrated solution (including audio and dvd authoring). But the future?
I mean its easy to get a solution that will suit you right now…but for some, you might also ask, will it be suitable for the future when I’m looking for potential post production work. Is editing something that you intend to do? Do you plan to look for work as an editor? If so, then Avid Xpress would be the way to go. Once you get the interface down, understanding the Avid workflow when going from offline to online to the bigger Avid’s is a pretty smooth transition. Generally, there’s just more work available for Avid editors (FCP is also getting a lot of attention these days). The market for PPro, Vegas, and Ulead just isn’t very big, at least, not yet.