What gaming desktop should I buy?

I have a pretty good budget coming in with around 700-800$. I have been using an alienware laptop for the best two years and a half and thought that I should really step up my gaming with a new PC. I'm very confused on what to get though. I want a computer where I can play games, not overheat, and multitask at the same time. I have been looking at the Lenovo - Erazer X315 Desktop - AMD A10-Series - 12GB Memory - 2TB Hard Drive - Black and was wondering if this was even a good CPU. I have no idea what to do and any help would be appreciated.

A10 series stink as a cpu. You want a fx series cpu and a r9 290x or a gtx 970m or better gpu.

Go to logicalincrements.com, and follow their budget for the amount you want to spend. $800 is a very decent amount to spend for a gaming rig, more than most people need, in fact. It's going to blow you away, the difference between the new one and your old laptop.