How about placing the monitor in the unit 'facing up-wards' and using a mirror at 45' to project the image forward? You'd have to have the image flipped horizontally before it's sent to the screen so that it appears properly.
You'll probably end up needing a converter like that. I haven't looked at "newer" monitors, but they are probably much friendlier. A lot of people have trouble with older ones since they have refresh rates like 15 or 20Hz and a lot of GPUs won't do that.
OMG! Thats amazing man, You should let me come play with you, Ive always wanted to play on a good one haha..Not just the crappy ones at the arcade. Im shocked someone has thought about this!
Just got off the phone with the company who i was going to buy the cabinet off and they said it weigh 500kgs and would need a forklift to get it off the trailer,and a forklift wont fit in my shed to get it there
Oh well,I guess i'll just have to keep my eye open for a standard stand up cabinet