I wouldn't focus on breed. I'd probably focus on the individual horse. If you aren't totally settled on a single discipline I'd look for something with, a good mind, athleticism and train-ability. That could be any number of breeds. 27 is young. If you want to show...show! I have eight horses. All lovely, all with their own strengths and weaknesses. My most versatile all around horse is an AHA/APHA cross. My least versatile horse is my imported German Oldenburg (he is very talented in his discipline, however isn't going to chase a cow or turn a barrel well and he'd look like a dork in a trail class).
It depends on what you plan to do with them, and your budget. If you're just riding for pleasure, then I'd say go with a quarter horse. If you plan on showing jumpers, hunters or dressage, then I'd say go with the thoroughbred or warmblood. The warmblood will however probably be the most expensive.