ignoral :
I just upgraded my monitor a year ago to benq gl2450 it runs on 60hz and I have been thinking of uprgading to gtx 980 now will I need to upgrade my monitor to get the best out of the 980? I cant get a 4k one
No you dont need to but if you want to....
My Top 4 picks
4: 1 or 3 ( depending on your budget) Asus g sync 144hz 1080p Monitors
http://goo.gl/0GWcbD
3: 1 LG widescreen Monitor 1080p
http://goo.gl/WXvvOJ
2: 1 Benq 1440p 60hz 1ms response time monitor
http://goo.gl/lhQXWX
1: Asus ROG Swift 1440p 144hz
http://goo.gl/rC2abo
I would recommend number 2 or 4 the most for you though because if you cant get 4k you probably cant get asus rog swift unless if you wanted to have a better framerate than the 4k on a single 980.
Update: You also can get 2 more of your current mon.