For someone who hates stereotypes, you sure threw out a few assumptions in your original post.
-Dressage is NOT making a horse dance. Far from it, and basic dressage should be the foundation of every discipline.
-You may come to find that you like those "silly tights" as they give you extreme freedom in the saddle. They are certainly not mandatory, though, and don't wear them if you don't want to. As far as jackets and hats (I suppose you mean top hats?), those are only used in showing.
Now that I am off my little box of soap.....
The only thing I am going to suggest to you is to take lessons. There is nothing like hands-on experience, which is what you need as a green rider.
ETA: You may also be dissapointed to find that when you first start riding, even if it is in a Western saddle, it is not going to be like those movies or reenactments. Just a warning. Best of luck to you and I hope you learn to love the wonderful world of horses.
"There's nothing more humbling on the planet than horses." --Sean Crocker
Last edited by Sunny; 01-23-2013 at 08:59 PM.