Jon,
Wow...so much to say and so little space to type it in.
First things first, start with a bow of around 40-45 pounds draw weight. It sounds light coming from your compound but you need to remember that you are holding 100% of 45#, not 15% of 70#. If you start with a heavy bow you will very likely develop bad form problems from using the wrong muscles and techniques to get the string back.
Next, a used recurve or longbow will do fine for you to start with and you can find tons of them on eBay for reasonable prices, and you can then sell it again when and if you decide to move on to something different or heavier. I would suggest that you try some friends longbows and recurves first to see what you like better, although a recurve will probably be easier to learn on, at least in my opinion, since it has a pistol grip like a compound does. Once you decide if you like a recurve or a longbow then you can get one to start practicing with.
There are a lot of good books and videos on how to shoot traditional bows out there. You might want to check out
www.3riversarchery.com as a starting point for those. The best thing would be to find a trad bowhunter nearby or your state level trad organization (
http://www.tradbowmt.org ) and find a mentor. There are probably dozens of trad bowhunters in Billings. Then go to lots of shoots and try out different kinds of bows to see what you like best and more importantly what you shoot best.
As for broadheads, they all work for trad gear, but I would stay away from mechanical heads as they take more energy that fixed blade heads. Two blade or three blade, it really doesn't matter, just what you prefer.
For arrows, a lot of folks will tell you that if you are shooting trad you need to have wooden arrows, but you can use aluminum or carbon if you prefer. Feathers will work better for you than vanes though, so don't try shooting vanes as they will make the arrow bounce off of the arrow shelf/riser when you shoot.
If you want to talk about trad bowhunting feel free to give me a call on my mobile, 443.994.1098. That is in Annapolis, MD.
Larry