I shoot authentic .44 Colt. I get the bullets from Western Bullets, but you might have a bit of trouble finding the .36 heelbased.
I did buy some from GAD one time but they were of extremely bad quality. If you are just getting started you will find that it is easier to load these cartridges than a lot of people say it is, as a matter of fact I don't see a lot of difference in them than a regular inside lubed cartridge. Of Course, you will need to order a crimping die. Good luck.