Would you use a traffic buying system on a good site?
 

If I wanted to buy traffic from a brokerage service like Choker for example, would it be better to make a landing page for that kind of traffic at a review site like mine, or is it better to spin off a new domain to send that kind of traffic to? ie: is it a good idea to keep a "clean" site free of this kind of traffic, or what?

You're fine landing it to your regular index page.

You can do a lander if you have a reason, too but traffic bought in bulk is usually traded/blind traffic so I cannot imagine why you'd do that vs. just modifying your actual site.

If you're worried about some kind of Google penalty of whatever you don't need to worry.

Plus, if you're looking for bookmarkers, you want to send them to your regular site.

Choker sells a lot of traffic for text TGPs or thumb TGps. A page that looks like a TGP with thumbs will work well with that traffic.