FDRX7, first measure your screen diagonally for exact viewable size. Then find your PLP layout choices in this group entry:
http://plp-gaming.wikia.com/wiki/Enormous_Medium-Light_PLP_Layouts#.7E42-.7E50-.7E42_1920x1080_1600x900_ALTYou will be using Manual PLP with your graphics card, unless you buy a new AMD card (e.g. R9 285, R9 380, Fury). There are instructions for manual spreading of many games, in my blog here & more on the PLP wiki. Eventually you will want to upgrade to get proper Eyefinity PLP support. I would recommend you peruse the wiki, to know exactly what to expect.
blog
http://www.wsgf.org/blog/imusrtPS
1. There is a ton of hang on the sides if using layout in Manual PLP. Make sure it's viable option for your desk situation. Otherwise you need Eyefinity PLP to make an H-shape (puts half the hang on top).
2. There is another idea, I have not tested: Use Windows 10 to adjust individual display sizes in your multi-monitor setup. This feature in theory would allow more screens to work well as sides, allowing you to pick a size you want. No guarantees...