I would recommend the cooler master, rosewill or thermaltake fans...especially thermaltake. Those are both very quiet and reliable fans. I've assembled a lot of computers using thermaltake fans and no problems with them. Very well made. Slower rpm does not necessarily mean less noise...all depends on the bearing that is used and the way they've assembled the fan. Most fans are going to make noise...its spinning on a bearing at high speeds. If you want a silent fan, get the Enermax UC-8EB. Not a lot of airflow though.
If you're looking at airflow you need to look at the CFM rating...the higher that is the more air is moved. Furthermore, most of those fans have a noise level in the specifications when you go to view the details on the fan. You would have to either get a power supply or you would have to hard wire into a 12vdc source. Radio Shack is probably the most economical place to buy a power supply. Good luck!