rslinking.com is a free script
http://www.besthostingforums.com/showthread.php?t=19068 is all on one page. you want users to download on a different page...gets to show more ads. you will need to because you will use a ton of bandwidth and resources as well as go through many rs accounts

mine is about $100 for the script. I can pass the script writers msn on if you want