Help me design my theater room

[cpaesq]

Ok guys take me to school! I know a lot about RPTVs and HD... However I'm getting ready to convert one bay of my garage into my dream HT room... and this includes a front projector.

So let me give you the layout of the room

10' 4" with
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- 20' 4" depth
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hight floor to ceiling is 7' 4" (tight when you consider I'll loose about 4" to flooring)


so I'm going to re sheetrock this room with 3/8" firecode sheetrock to help increase the reverberation in the room, and frame out a chase allong both walls for the cables, speakers and power.. I also put a 50 amp breaker into the service pannel to handle the power to the room

Now given the dementions:

1) what size screen could I get away with?
2) how far back would the first row of seats need to be?
3) I want a good projector with HD and some sort of line doubling
4) I'm looking to spend 2-3K but if there is something better I'm willing to consider it.
5) What else do I need to know when designing this room that I should do in the planning / framing phase to save me headaches in the future.

Thanks for your help and I look forward to being a front projector owner soon :)