Just chasing some ideas for wiring up a theatre room with projector

Need some ideas of a quality way of hooking up a projector mounted on the roof at back of the room with video source at front of the room.

Now what makes this task slightly harder and a once off thing is the room is going to be on the bottom floor of the house and once the roof plaster board goes in ill never be able to get into that section of the roof again. Being that there is a 20cm gap then concrete slab for top story.

So I need something that is easy to get a cable of some length and that retains the quality. Obviously im only going to run the one cable to the projector and then just select the source

Now am thinking DVI/VGA or HDMI.

now thing that makes it slightly more difficult to choose a cable type is how they are ran through the walls and if they have plates on the wall to plug into or one continuous wire to the unit ??

Just need some ideas please any one wired there house up with a projector

Thanks.