Given allot of games are ports nowadays your more likely to have problem with getting 16:10 support then 16:9, that said its extremely rare to have a modern game not list ether 16:10 for 16:9 resolutions. The only real difference will be if they properly correct their FoV for the different aspect ...
I've been very happy the last 4 years with my Samsung 4:3 monitor @ 1600x1200 and have resisted going widescreen because I felt like I'd be losing something (specifically, >100 vertical pixels) by going widescreen at 1680x1050 or 1920x1080. I'd want to go 1920x1200 if anything, but those are too ...