So I went cross country schooling over the weekend for the first time ever. I didn’t expect to like it because I’ve never been a big thrill seeker, but my horse and I had a blast, and now I need to start investing in equipment. I borrowed a vest from a friend but it was too short so I want to pick y’alls brains on how to find the right fit. I’m 5’10" and broad, but also kind of thin and flat chested, what make would you recommend I try? All Dover has in store for me to try are Tipperary and I wan’t to make sure I explore all my options before I buy one.
Welcome to fun/dark side!! 
I bought my RaceSafe ProVent 3.0 vest because it had way more “off the rack” sizes than the standard Tipperary options. I have the opposite problem to you - my upper body is really short - but the RaceSafe has more sizes based on your measurements and I find mine more comfortable and cooler than my previous Tipperary vests. They also come with shoulder pads which have decent evidence that these offer significant protection from broken collar bones, so that was an added bonus for me. I ordered mine from the UK, which was cheaper than buying it here (even with shipping), but that was a few years ago so prices here may have gone down!
Racesafe have the most options.
Welcome!!! I’ve been very happy with my tipperary pro. I’ve migrated to wearing it all the time, not just xc, and the tipp is comfortable and holds up. I’m built like you are and the small was fine.
Champion Titanium are very adjustable and comfortable.
