Just get jodphur clips from a tack shop or Amazon. They have a lot on Amazon, but a tack shop catering to English riding should have them.
Dude. How did I not know these freaking things existed?!?
I don't know, especially in Texas. I live in horse country and a few friends that have farms got me into the tack shops. The leather in those places is amazing. Some of my best wallets and purses are tack shop finds.
I have done horses most of life, these have been around forever. They work well but I find that cropped jeans are awesome for boots. I have an older pair of very slim cropped jeans which are my goto jeans for tall boots.