IPS or 120hz

I trying to decide if I should get either a Dell U2410 or HP ZR24W now or wait until either the 27 inch 120hz Samsung SA750 or the Acer HN274H comes out. I have a 22" Dell 2208WFP now (1680 x 1050) and I want a bigger screen. The 24 inch 120hz screens don't look much bigger because the are 16:9-they are just wider. The 24 IPS screens look like a better upgrade since they are taller and wider. I mostly will be using the monitor to play games such as Bad Company 2 and fast twitch games like UT3 (a dying breed though). I leaning towards the 27 inch 120hz but not if they are going to be over $600. The 120hz have smoother game play but I heard you can pick out player hiding in the brush better with an IPS monitor. I hate waiting and find out they are going to be $900. Then I will be deciding between those or the U2711 (if I had the money). The Samsung SA750 with its thin bezels might be good for eyefinity if I decide to do that in the future.