i can get you a link to purchase printshop 6 but whether it is compatible with vista i dont know. it was never really rated that way. It was designed for 95/98 nobody ever tested it for vista because they were about 10 versions higher by the time vista came out. nor did they do a complete list of compatible programs the way they did for windows 7.
there are definitely people that had problems but not the same problems. some couldnt load it at all and some could run it but couldnt print from it. some just had it work with no problems.
this is the link to purchase it
but i would strongly suggest going to a version that is designed for vista.