Ya know? I did a wagon, and was looking for my next toy. I saw a Buick Hearse at a used car lot. It was a LeSabre. Lucky for my girlfriend, it was gone, or else I probably would have brought it home. That would make a great choice.
Does it really matter what kind would be the best? I mean do you really have a choice? Where I'm from, we don't have used hearse lots. But seriously, I would think your best bet would be a GM, more parts would be compatible, although Cadillac would require a little more work than that LeSabre that I saw. Good Luck. Not only can you post about your kills, but you can cart them away when you are done.
Brian