Check out the Antec Super LanBoy and the ThermalTake Xaser Lanfire. They're both not that good looking IMHO but very functional. They weigh about 8lbs. dry and neither come with a PSU I think. The Lanfire is more expensive and doesn't feature placements for 120mm nor dampening for the hard drives like the Super LanBoy does, but it's a well built case (so is the LanBoy for that matter though

). For PSU, don't skimp because it's one of the most important parts for a system. Brand and quality is more important than wattage. I would recommend the 350W by Fortron or Sparkle (same manufacturer) w/120mm fan from Newegg or TTGI 350W unit with the 140mm fan at Directron. Should be $40~50 for one of these, but it is worth it. Very quiet, clean power that should power just about anything you want to throw in there short of a dual CPU setup
As far as size, I was never a fan of MicroATX offerings so I can't recommend a very small case. But the above cases are light and the Antec comes with a tote strap for carrying around. Good luck :beer: