Some of the best Star Wars kits are the Fine Molds ones. They are a bit pricey, but excellent kits. AMT/MPC did both an AT-AT and Star Destroyer as well as many other subjects, which can still be found on e-bay I believe.
I have found this site an excellent source, he has review sof the Star Wars kits he has built.
www.starwarsmodels.com/models.html
I built the AT-AT years ago, unfortunately I don't have it any more. It was a nice kit and comes with tiny snow speeder's.
I am a Norfolk man and i glory in being so
On the bench: Airfix 1/72nd Harrier GR.3/Fujimi 1/72nd Ju 87D-3