I think the reason no one responded is because they have no way of providing you with honest and accurate advise.
For a start there is not enough information about your current set up, how much memory does your system have. Memory is key to such large screen real estate.
And without doubt your CPU is going to be the bottle neck. Would say it is a bottleneck at the minute with your current set up. So not sure how adding or upgrading a graphic card is really going to make much difference.
What I am surprised at is that the AMD guys have not even responded at all. So for that I am offering an apology.
I really like the CPU by the way, I have one and they are like gold on ebay. You would get pretty much your purchase price for one I have found if you listed it.
I would not be able to offer advice as to which AMD CPU will be the best way forward as I do not game with AMD. I have gone over to Intel for gaming.
To help us help you - please provide as much information about your system and the problem as possible.