I'm using a 27" Toshiba flat screen with component in. It was an expensive TV, not purchased specifically for the cabinet (bought it for XBox that I never play). I didn't use any service menu tweaks, or even Powerstrip to get my final setup working. I did experiment with Powerstrip before figuring out what worked best for me.
Using a Radeon 9550 with the DVI to component adapter, I just had to specify a custom resolution within MaLa (front end). I suppose if there is any drawback to this, it's that Windows is not running in this mode, so the image is overscanned until I'm actually into the front end. The monitor is vertical and the Windows desktop is sideways, so I use another PC to do most of the admin on it anyway.
If you want the custom resolution available all the time, Powerstrip may be a better solution for you.
640x432 sizes the image correctly for my TV in component mode.
I far prefer a tinted bezel over clear. It helps hide the surround around the TV, and also helps make the image not so "TV like". Component is far better than S-Video, but I still found the image a little harsh looking without the tinted bezel. Tempered glass is probably the best option, but I had tinted plexi readily available, so I went with that. Just have to be careful cleaning it to avoid scratching it up, as MaMeNnO alluded to. If it end up being a problem, at least I'll have something while I find a good source for tinted tempered glass.