Wow, you've been through the ringer with him haven't you! But good for you for sticking it out with him and wanting to fix things.
I study Parelli myself and think it's wonderful you are wanting to get into it. It's a wonderful program and I believe in it 100%. I understand not having the funds to buy the DVDs directly from Parelli. Have you looked on Ebay? You can usually find things on there for good prices. Just type in Parelli in the search box.
I would definitely invest in the halter, 12 ft. Line and stick. It's a very good investment and the stuff will last you forever. If you do find DVDs at a price you can work with, I would suggest you get the Level 1 pack. That's the best way to get you on your way. At the very least get the 7 Games DVD from the Success Series.
I'm sure you've already checked out their website, www.parelli.com
That's got tons of information for you to look at. You could also look up an Instructor who is near you or who will be coming to your area for a clinic that you could participate in or go audit. I highly recommend Carol Coppinger, Gena Warrington and Aimee Brimhall.
Have you thought about joining the Savvy Club? It's $25/month but the support from the Savvy Club Forum and the educational material is priceless!
You could also do a Yahoo Group search to see if there are any Parelli support groups in your area. I helped create the St. Louis/Illinois Parelli support group on Yahoo and our members are the most supportive and positive people.
Does that help any? Do you have any specific questions? Feel free to PM me if you want to! :)