How can I get best video with my InFocus LP640?

I am trying to set up a home theater with the best possible video quality coming out of my InFocus LP640. I can get s-video to work just fine but want to use either the M1 or VGA inputs for a higher quality video. so far i can't get anything but a computer to work in these inputs.

My gear:

-InFocus LP640 projector ( http://www.aboutprojectors.com/InFoc...projector.html ) with:
1 x S-video input - 4 pin mini-DIN
1 x composite video input - RCA
1 x VGA input - 15 pin HD D-Sub (HD-15)
1 x VESA M1 - M1-DA


-Toshiba sd-3900 DVD player ( http://reviews.cnet.com/dvd-players/...-20847696.html )
with:
1X SPDIF output ( TOSLINK )
1X S-Video output ( RCA phono )
1X Component video output ( RCA phono x 3 )
1X SPDIF output ( 4 pin mini-DIN )
1X Composite video/audio output ( RCA phono x 3 )

-Joytech control center 540c ( http://www.geeks.com/details.asp?inv...881035&cat=TVS )
-Xbox 360
-modded Xbox with RGB component cable

Cables and adapters:
-25 foot DVI-I to RGB Component cable ( http://www.monoprice.com/products/pr...seq=1&format=2 )
-DVI-D Female to M1 Male adapter ( http://www.monoprice.com/products/pr...seq=1&format=2 )
-M1 Male to VGA/USB Male adapter ( http://www.sears.com/shc/s/p_10153_1...=SPM6208837902 )
-VGA Female to DVI-I Male adapter
-VGA Male to DVI -I Female adapter
-VGA Female Gender Changer

-I have many 6 foot DVI, VGA, component and composite RCA's, and s-video cables lying around but i need at least 25 feet to my control center.

whats the cheapest way to get HD signal to my projector? or should i just give up and buy a long s-video cable? will i see a big difference?

why would those work and not my M1 to DVI adapter with my DVI to component cable?

-DVI-D Female to M1 Male adapter (http://www.monoprice.com/products/pr...seq=1&format=2)
-25 foot DVI-I to RGB Component cable (http://www.monoprice.com/products/pr...seq=1&format=2)

can anyone tell me? i dont wanna waste money on yet another cable if it isnt going to work.

well i went ahead and bought that cable from monoprice. it didnt work. it does work with my computer though. can anyone please explain why my computer works in these inputs and not the rest of my gear? how can i get em working?