When it comes to old PPVs, pawn shops, garages sales, and flea markets are your best friends. Also, some of the old independant video stores may sell them. There's one in my ex girlfriend's old neighbourhood that rents them or sells them, along with dusty old NES games, too. Yes, seriously.
I've been waiting for the early Shotguns to pop up on The Network. I remember really liking the concept. I don't remember a whole lot from these off the top of my head. Austin getting pissed at a rambling Terry Funk might be my favorite memory.