IMO a 22" 16:9 aspect monitor is probably not going to make you happy. The viewable area for horizontal games will be about that of a 19" CRT monitor (which is close to a 17" 4:3 LCD in viewable size), and vertical games will be comically small. If you use a 4:3 21" monitor, you will have about 44% more viewable area for horizontal games (not as big as a 25" CRT, but pretty close) than with a 22" 16:9 aspect monitor.
You can get a 20"-21" 4:3 LCD monitor with a very nice IPS or PVA panel off of ebay for $100 shipped if you look carefully. The monitor will have a much larger usable area for retro games, fit a standard bezel, probably have a nicer panel with better viewing angles, and will overall look much nicer/authentic in the cabinet.
Heck you can get a 17-19" 4:3 LCD with a nice panel for less than $50 shipped (I picked up a 17" 4:3 NEC with an S-IPS panel for $45), and it is also going to be much nicer for retro gaming. Given how important the monitor is to your cabinet, spending less than the cost of a U360 joystick on a nice screen is worth it IMO!