Advice on basics and Reining tips please...very important?

My little mare moves amazing off of the rein, and she really has a good w/t/c in her. Myself as well as others think she would make a great little reiner (just for fun shows etc). Some info on her:

Age: 5yrs
Breed: APHA
Height: 14.3hh
Pic/Videos:
http://s943.photobucket.com/albums/ad272…
(the first 2 videos and 3 pics are from 2 summers ago, her first show ever and she was 3...the rest from a show this past summer.)

She is completely broke and bombproof, but I am having a hard time trying to figure out and train lead changes, and how to stop on the hind end (sliding will have to come a bit later). Could anyone give me some advice?

She is a good stopper, but she uses her front end way too much...I can feel/see it and idk how to correct that and help train her to stop on her hind end more. She also seems to really favor the left lead. At the lope I always find myself having to support my left side a bit more...is there a way to work on this? Please, any advice helps. With winter coming Id like some good excersises to work her on that can help us both and perhaps aid in showing for the Spring.

I think your best option would be to find a good trainer in your area. There are so many little things that would be impossible to explain over the internet that go into reining, like making sure they are using the correct pivot foot in the spins, keeping the front end pedaling while the back end sticks the slide and other little things that account for so much of the basics. Only thing I can say is that if she favors the left lead, then her right lead isn't strong or balanced enough and she would benefit from a ton of circles on the right lead.

I figured I would get alot of that, and I understand, but I am not looking for help on pivots and rollbacks etc yet...just the basics of lead change and stopping on the hind end. Any small tips would help immensly. I don't hit my horses with a ton of hard new things to learn at once, I like to take it slow step by step so even the littlest things would help.

I am no help on the led changes, other than to say I would probably get her stronger to the right first.....

As far as the stop goes, what my trainer has been doing with my guy to train him is to make sure that when you ask for a stop, it has to be NOW, not in a couple of strides, and back them up as soon as they are stopped. He has said that this gets them back, since they are ready to back up when they stop.