Dude, there are like SEVERAL kinds of cars out there...what are we talking here?? Honda? '52 Chevy? Dumptruck?
Keep it all Ford. Use '40-'48 backing plates, hubs/drums. What are you using up front? If it's early Ford, try to get the rear to match. Look out, '40-'42 hubs/drums are different to '46-'48. If you ever think you may go for Buick drums in the future, go for the '46-'48 set up.