I don't know anything about the Bushwhacker brand, but here's my two cents:
The Bushwhacker panniers depicted look like they could be ok. There are no dissatisfied Amazon reviews. And they have a retro pannier look about them, if that's your thing. But the photos don't show the mounting system, and zippers can be a problematic closing system. You have to have the things packed "just so", otherwise it won't close. A strap-down fastening system that most modern panniers have is easier to close, as the straps compress the load and also offer better opportunities for overstuffing the bag. (Not that it's advised...
If I were to pick up a set of bags in that price range and with the same capacity, I'd check out Axiom, which puts out some great budget gear. Maybe give these Axiom Seymour LX panniers a shot:http://www.axiomgear.com/products/gear/bags/panniers/seymour-lx/
While I haven't owned this particular model of panniers, I've owned several sets of Axiom panniers over the years and put them through a lot. They didn't let me down. The mounting system looks pretty solid on the Seymour LX and it is fastened by straps.
You can most likely order the Axiom bags through your LBS.