Rs550 shortest brushless equivalent

[Supermotolew]

Hi eveyone! Those following my build thread will see im having some real estate issues in my design, it would also benifite from a higher voltage.
Im Currently using TeamSC batten boxes which so far i love but im having issues with space and would like to find the shortest possible brushless equivalent withought compromising specs.
Has anyone done this? Maybe a generic 3536 Any thoughts?