Regarding screen size: It might help to spend some time at
www.displaywars.com so you can make some comparisons. Then you can see how big your image will really be. Our last build had a 39" screen which gave us the equivalent screen size as an old 32" 3:4 tube screen. For vertical games it's similar to a vertically mounted 23" screen. And obviously it's a 39" screen for widescreen games and content.
The 39" screen works just fine and doesn't feel too big or look bad. But I wouldn't go any bigger unless it was a pedestal design and the screen was farther away. This build was very loosely based on Chance's Flynn's arcade cab and some other slim/wide builds. There are several of them in progress right now in the projects forum. In our case this build needed to be a little oversize because it's hiding a door (partially revealed in the attached pic).
I'd recommend tinted glass or plexi for a lot of reasons. The tint cleans up the cab and obscures the fact that it's just a TV in there. There are many threads discussing it if you search this forum. If you're concerned about getting a CRT look out of an LCD, the tint helps a little, but you'll get more mileage out of some decent hardware/software shaders and a good high-res screen.
I think 22" is too small - even for a two player cab. Especially if it's 16:9. For 4:3 games that's an 18" screen (or about an 11 x 15" rectangle). But that's just my opinion, lots of classic arcade game had screens that were about that size.