In my opinion, as long as the horse is capable of performing at the level and discipline I want it to then I don't care about breed.
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).
What's your thoughts on Tennessee walkers?
Quarter horse. Their more sturdy and are all rounders would be a GREAT first horse! :)
Thoroughbreds have a thinner skin and get cuts and scrapes and what not more easily (hard lesson learned for me haha) For your first one I'd go for a more laid back breed whose a bit more tougher
I'm not completely sure what I want to do yet. I love dressage and jumping but also enjoy trail rides....I'm 27 and feel like I might be to old to show anything more than just for fun....
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.