Also max damage is 24-33. That is a must or mare is ruined.
I would go to uo-cah.com use the pet panner, so you know ahead of time where exactly to allocate points. A priceless resource it is, use it and it works nicely. You probably only need 500-600 str. No regens in picture also. Those usually need be 20-5-30 depending on build.
Use uo-cah pet planner and post that here, asap before you finalize. PP mares are hard to come by.