You can use any traffic trade script for a blog. It really just depends on what kind of features you need.
If you just want to trade traffic and have a toplist on your blog, I personally think that Slothtrader is a good one.
If you don't need to analyze trades productivity, I would suggest you to buy a license for Links Organizer. It's a link trade but you can also use it as a traffic trade script as well. It can output a toplist depending on the number of incoming hits or uniques from an hour to more. Why I suggest you such a script? Because you can also use it to trade traffic or links on your other sites.
