You sound really excited cbearden. It's a lot of fun working with this stuff. I don't know your background or what kind of equipment you have, but with an old hermetic compressor you can fashion a recovery machine for cheap if you aren't worried about reusing the recovered refrigerant. I haven't built one, but there are others out there if you do a little searching. These homemade jobs probably aren't as good as the industry machines; at least you aren't venting the gas and you recover the vast majority of it. Don't know enough about it, my dehumidifiers were all leaked out when I got them.
As far as charging with propane, there are some good threads on here about that. Safety is number one. I'm sure you will use the utmost caution and care when you're working with a flammable gas.
After I installed a piercing valve so I could purge any remaining gases out of the system, I removed that hot gas bypass, fixed the leak in my system, install two access ports, I did a triple evacuation after I was pretty sure it was leak proof and charged it from a Coleman propane bottle. You'll have to find a way to adapt a propane bottle to 1/4" flare. I charged as a vapor, but I guess you should charge as liquid to avoid any non condensables that might be in the bottle.
Just be careful. Ventilate well. Make sure you purge well before doing any brazing. Have fun!