Just about any old wagon or van roof will do. Dodge Caravan's are a very popular donor roof as well as many station wagons. Plymouth Voyager (Caravan twin) would also be a good one.

However, I have also been told that Howell's Sheet Metal has made roof patch panels for some roofs, but mostly Fords. Have heard both favorable and unfavorable reports on their workability. Their web site is http://www.fordor.com You can check them out but a van or wagon may be your best choice.