It sounds like you should be in the market for lots of lessons on a school horse before looking into eventing. Especially if you're looking to get a TB to do it with. Lessons are great for everyone. It doesn't matter if you're a grand prix jumper, a trainer, or a high level dressage rider. Almost all high level riders have trainers helping them and teaching them.
I have had very little success with TBs, personally, but that's just me. I am loving my Appendix QH because he's got the athleticism of a TB and the cool mind of a QH.
Proud mommy of...
Bailey- Appendix Gelding|Satin- Morgan Mare| Teka- Reg. Paint Mare|Shiloh- Reg. QH Mare| Misty- Reg. Pinto Mare