Graphic card upgrade recommendations for Dell XPS 9100 (workstation)

[ren0901]

Currently have a AMD Radeon HD 6800 Series (http://www.amd.com/en-gb/products/graphics/desktop/6000/6850) driving a Dell 2407WFP and a 22" display (2560x1600 max resolution).

I'd like to consolidate to one display like a LG 34" Ultrawide (http://www.lg.com/us/monitors/lg-34UM95-P-ultrawide-monitor) 3440x1440 max resolution.

This is a work PC, so won't be doing much that is graphics-intensive. Just like to keep a lot of windows open (Quickbooks, Excel, chat, browsers, etc) and watch an occasional video.

The power supply is 525W.

 

[Zectorr]

There is a Nvidia GT 730 1GB or 2GB low budget card , stays cool most of time wont get hot (quiet) .
also if you can pay more then go with the GTX 750 ti or if you want a AMD card go with a R7 260x