In most competitive sports you are over the hill by age 30. Equestrian sports are different; people can and do compete at upper levels, even the the Olympics in their 50's. For most people, cash and time are the limiting factors in the equestrian endeavors. Not many people can make a comfortable living training other people's horses. Concentrating on your career now will help ensure you have the cash to pursue your equestrian interests later.
From age 21 (graduated college) to age 50. Could never have afforded a horse of my own until then. And I had wanted to build my career around horses, parents convinced me that this was NOT wise. They were right. Very few people can.
What's wrong with you?? Your cheese done slid off its cracker?!?!
Listen, I know you didn't ask for the rest of the advice I'm about to give, just about the horse thing. So first I'll say "yes, I've spent time without access to MY horses."
Next? Take the job! You are at a place in your life with minimal responsibilities. No mortgage. No kids. The only person you have to think about is YOU. And YOU will get down there, have a moment or two of regret as you adjust, then you will LOVE IT. And you will wonder why in the heck you even thought about NOT going. Even if you totally hate the job, you will have a life experience that will change you and become a part of you and it will help you later on!
I have lived/worked overseas a few times. (without taking my horses) They have horses pretty much anywhere you could possibly go. Including Costa Rica. Further, getting some international business experience is HUGE.
You wouldn't believe the kinds of doors that can open up when you've got stuff like that on a resume. AND, even if you don't end up working another day in your life once you're home, you will have pretty cool stories to share.
Do it. Do it. Do it. GO!!!!! If there are friends or family who are whispering in your ear that it's a long way from home, what if, what if, just ignore them. Go. When I first moved to Italy, my grandparents quit SPEAKING to me. My mother freaked out. My friends thought I was nuts. It was AWESOME!!! When I announced that I was moving to Mauritius to start a company, same thing. People thought I was nuts. Ten years later, as I again face moving overseas, my family is sufficiently "broken in" and planning on visiting. Finally. It's so worth it. Do it!!!!
The horse stuff will work out.
I used to jog past a farm when I lived in Italy just so I could smell horses. And when I lived in Mauritius I went to a riding club to ride. Pretty freaking cool. You can find horses.
A good horseman doesn't have to tell anyone...the horse already knows.