If you are looking to get a projector the first thing you need to do is learn a lot about projectors and what is appropriate for your room and the setup you are trying to achieve.
If you get a 800x600 projector (VGA) then that is all it will EVER display. Sure, it may accept higher resolutions like 1024x768 or HD resolutions of 720p or 1080i. Heck, the projector MAY even accept 1080p.
But, all it will output, EVER, is 800x600. That is the native display resolution of the projector and it will never be more than that... and it will never be less than that.
You should be buying a projector designed for use in your home theater. This means, a home theater projector. Take a look around
www.projectorcentral.com for a few hours. Read reviews, read comments, check the forums, read the FAQs, etc. The bottom line is that a business class projector like a VGA projector, is exceptionally cheap in many regards and won't come even close to the quality of most projectors designed specifically for home theater use.
Think InFocus SP4805, Sanyo PLV-Z4, Panasonic AE900, Optoma H27, at the very least.