Either of the engines you noted would provide pleanty of power for your needs. They are just physically a bit larger than you really might want, but it appears you have a good plan to account for the extra weight.

The Jett SJ-60L "Hover" version and the BSE-76L are both "40" size engines designed specifically for 3D flight and aerobatics.

Yes, they are a bit more than the Tower 75, but these are the same size and weight (appx) as an OS46.

The 76L turns a 14x4 well over 10K rpm. The 60L-H will turn a 12x4 up over 14K rpm.