UniWS won't let you get 1280x800 (KotOR freezes when you try to run this resolution). 1440x900 is a nearly identical substitute that doesn't cause the game to choke and die when you want to run it.
1) Download and run UniWS
2) Select "Star Wars: KOTOR (1024x768 interface)" from the drop-down.
3) Use the file window to browse to your SWKotOR folder
4) Enter "1440" for Width and "900" for Height (without the quotes)
5) Click the Patch button.
6) Download the 1440x900 HUD Correction patch
7) Extract to your Override folder
another screenie with the HUD up.