I think that I'd be interested in playing a forum game of Ars Magica.
I'm quite familiar with the rules and I have a [strike]fairly[/strike] complete book collection.
I wouldn't want a game that demands I post more than twice a week although I do expect to typically be able to post more often than that.
I've never been involved in a PbP or PbEM game that didn't collapse at the beginning and never accomplish anything of note, but I don't believe that it has ever been my fault.
Please pm me if you've room. I don't check these boards regularly but I generally do post to the Ars Magica board on a daily basis so I am around.