Lets cool my Antec 300

For the 140mm fan, I'd go with a Yate Loon DS14SL. It's quiet, cheap, and reliable. For the two 120mm, the Xigmatek XSF-F1251 puts out a good amount of air for the price. The 80mm fans, the Delta 80x25 is powerful without the noise you get from the 38mm versions. If you don't mind the noise, the high power Delta's are great, but you pay a lot for them.