Cinch Tie Saddle

I'm going to start some showing in high school rodeo (20x) this summer. But right now I'm learning to rope and tie goats. (I already barrel race and pole bend.)

Where is a good place to buy any roping supplies I will need for my horse, a rope, piggin string, etc.

(Right now I ride in a barrel saddle with good quality saddle pad, breast collar, barrel racing bit, bridle and roping/gaming reins - plus splint and bell boots - I will ride in a flank cinch when I find one that fits my chubby horse.) =]

I have an instructor with experience in the events, so if you have any other advice please add it!
I'll only be doing breakaway roping, not regular calf roping. My saddle now is fine, I just wrap the horn when I rope.

In breakaway roping the rope is attached to the horn with string, so when I rope the calf it will break off easily. It won't do any damage with the wrapping.
(I've talked to a pro about wrapping the horn.)