Questions about Tailored Sportsman riding breeches....?

OK so I'm on a college IHSA team and this year for Christmas I'd really like to ask for a pair of nice breeches. It seems to me that Tailored Sportsman is a really popular brand as well as Ariat. So I've been trying to scope out those two brands. One of my problems is I'm not 100% sure what size I'd be and there is absolutely no stores anywhere near me for me to go try things on. I tried on a pair of Tailored Sportsman 30 regulars from my friend but they were kind of tight at the waist and then super baggy around my hips/upper thighs/crotch area, so I don't know if they're too small or too big! The other problem is I'm not entirely sure what all the differences are between the different types of Tailored Sportsman breeches. If I'm planning on using these mostly just to show (and mind you I really don't show THAT often maybe 5 times a year) and to practice in a little, what style would be best? I'd really like to get some good quality breeches to last me a while but I also don't need the absolute top of the line and I don't want to break the bank on just one item. I will probably end up buying from somewhere online so any advice, or tips, or even a Tailored Sportsman Breeches Sizing Chart link would be greatly GREATLY appreciated! Thanks!