If the upgrade is for gaming, you will be limited by what CPUs are available for that FM2+ platform and the PSU you have now. I see the specs state a 350W PSU, but that doesn't tell us much. Total wattage means very little and is often over-rated. The make of the PSU is more important as is the +12V rail specs on the PSU nameplate.
But I would suggest that if you want to keep most of what you have now, a gfx card upgrade along with a better PSU would be the way to go. The 350W PSU is about at its limit with the GTX 750 Ti.
A platform change to Intel (preferred), would entail a new motherboard, possibly new RAM, and a clean install of the OS and all your apps... along with the fore-mentioned PSU and gfx card.