Yea both of those LCD's are great for gaming. They have a good response time, good contrast, and 19" is great. I'm actually planning on upgrading to a 19" LCD this Christmas. I'd go with the cheaper one just because the difference between 8ms and 4ms really isn't worth the difference in price, that's just my opinion. I'm pretty sure you can mix a CRT and LCD and run dual monitors but i'm not exactly sure...
AMD 64 3200+ Newcastle@ 2.2Ghz
1GB (1x1GB) OCZ Performance Series
ATI X700 Pro 256MB OC\'d 475/525
OCZ Modstream 520W
Samsung 914v 19\" 12ms LCD
SB X-Fi w/ Logitech Z 5300e