Should i get a 120hz monitor?

[horche]

Hi guys . So what i want to ask you is: Should i get a 120hz monitor? My rig so far is Phenom 955 with 4GB 1600hz RAM 770TA mobo and 7950 OC/660ti Jetstream videocard ( I haven't chosen yet). So should i get a 120hz monitor (and which one)+660ti Jetstream or a regular 60hz monitor and a 7950 OC? I will upgrade my rig to a i5 3570k and an ASrock Extream mobo in a 2-3 months.

 

[horche]

I totally forgot... I will be playing FPS games on my new monitor and i may be upgrading to a crossfire 7950s next year (because the 2 cards are too expensive).

Cheers!