There is a section for buying and selling accounts here: http://www.mpgh.net/forum/forumdisplay.php?f=567
I would suggest titling it "Looking for perm para account", with the WTB prefix.
In the actual post, say that you want an account, any level/ any sd/ any win-loss ratio with a permanent para.
I don't know how much it would cost, someone else might be able to tell you. I'm assuming skinned versions of the para like the milad or tortoise would cost more, but don't dismiss those as potential buys.