Build it yourself unless you want a lot of special things, which you don't have.
It'll save you a bunch of money. Get most of the parts from Newegg.
No, they just make the GPU. The card is made by someone else. Who's the manufacturer? If you don't know, don't buy it as it's like flying blind: you don't have a clue where you'll land.
Asus and Evga are my preferred brands.