There is a PCA forum that might interest you, though not sure it's very active.

http://health.groups.yahoo.com/group/PCA-RX/

Personally, I have found everything in Andy Cutler's book on Amalgam Illness to be true, and I trust his protocol more than anything else. I believe it to be the safest, though probably not the quickest or easiest, way of removing mercury. It is also probably one of the cheaper ones if you do ALA only. I guess the best thing you can do is read and read - these are good forums

http://health.groups.yahoo.com/group/frequent-dose-chelation/messages

http://health.groups.yahoo.com/group/adult-metal-chelation/messages

... and make your own decision. Good luck.

Nicola