You said you want to save your budget for lessons. With the OTTB I feel it will take more lessons to get where you want to go. I know you said you can bring young/green horse to a certain level. If you can get a horse to N in decent form on you own or with minimal help from a trainer then I think the pony is a better bet.
With the pony you could save more on lessons, i.e. take lessons only when YOU, not the pony, needs help. You could save money on lessons and put it into schooling sessions and shows.
I hope that makes sense!
The pony looks very easy going and a fun ride!
GL witth PPE
I vote for the pony. I have 15 thoroughbreds, and I think the pony is a better pick.
The pony will be a nice ride, the type you can tie to the trailer all day. That is how I decided on my show prospect. He is safe for me, even though I like a hotter horse. He is still very athletic, but if I wanted I can tie him to the trailer and he will be fine. He is not a nervous horse at all. He will ride down the road by himself. So much less drama then my other tb.