Hi Tommy
The HC3 doesn't seem to be an ideal projector for watching movies on, it has a low contrast ratio which will mean blacks will be more like dirty grays and that can severely degrade the perceived picture quality.
It is also severly limited as to the inputs it has:
15 pin d-sub
s-Video
Composite
Composite is unwatchable on a big screen, so that leaves just two and S-Video isn't exactly great quality either. I'm not sure what receivers there are that'll take VGA outputs (nor for that matter do I know what outputs the X-Box and PS2 have), but S-Video is probably okay for those .. leaving how to connect the DVD player. You may need to buy a component->VGA converter, if such a thing exists or have to settle for S-Video for that too.
Frankly, I think you may have problems getting all your kit connected to this machine with any degree of picture quality, it'll be BIG but not necessarily BEAUTIFUL

.. but I'm far from an expert in interconnects (not having any consoles) and receivers so there may be a simple answer.