Just as the title says. I am looking to spend about $250, and want to know which of those is the best bang for your buck. I know that 250 aint much, but it's not worth it to sink anymore into it. Other than this, it is 100% stock. I also appreciate people suggesting other items that fit within my price range.

Edit: The car has almost 200,000 miles so the stock cat is probably clogged. A downpipe would fix this, and eliminate the U-bend.