Offshore clicks is good. They have great support and use a Varadox dialer.
They give many premade ways of linking to it, including the usual autoinstall active X etc.
Also has a neat feature where if someone starts to download it and decides to hit cancel, it will then redirect them to a page of your choosing, so you don't lose traffic if they are too cheap to pay! (send them to a join4free full page ad!)
Give it a try:
http://php.offshoreclicks.com/cgi-bin/ref.cgi?evildick