Upgrading LCD 17' to 22' questions

As of today I am running a 17' Samsung SyncMaster 740B that I bought over a year ago (to replace a dead CRT), on a system with the following specs:

AMD Athlon 64 3200+ 2.0ghz
Asus A8N-VM CSM
Thermaltake 430w PSU
1.5g Kingmax DDR
Sapphire ATI X1950 GT pci-e OC'ed *edit* (500/600 default, playing at 621/675 without crashing)

I did a bit of research, and couldn't find the answers I was looking for. I wanted to get a Samsung 226BW 22', but couldn't find any good deals (by the way, does anybody know a good place online to buy parts? I live in Canada and I don't believe Newegg ships here). The best I could find was $379 cdn if I remember correctly, and my usual place had it for $399. However, I was also considering a 225BW, the cheaper Samsung for $309 cdn, which seems to have positive reviews. Before I decide on anything, I would like to get as much info as necessary. I was wondering:

a) Would my current setup be able to efficiently handle any 22' LCD @ full res w/ AA-AF + max details? And if not, does the next lower widescreen res look that bad and would I just be wasting money on a display that my comp doesn't have the muscle to use?

b) There are a few differences between the 225 and 226, with the key difference being their response times (5ms and 2ms respectively). Is it really worth an extra $70-90 cdn for the 2ms alone? Is 2ms that much better than 5ms? Or is the overall performance of the 226 worth its price over the 225?

c) Does anybody have any other recommendations for a 22'? I was also looking at the Acer AL2216WBD\, BenQ FP222W + FP222WH, LG L226WTX-BN, Viewsonic VG2230wm + VX2235wm.

ALSO my PC is used mainly for gaming; FPS (mostly BF2, with a bit of F.E.A.R, DoD:S, CS:S) and a bit of Oblivion.

Any help is appreciated. Thanks