The best small AP board with Visual odometry support?

Hello! In my research i use NAVIO2 board and a companion computer for visodom and etc, and cause Navio2 based on Raspberry, all computations were distributed between two computers. All works nice. But now i move all computations on a companion and thinking to migrate to more mobile (may be FPV like) AP board in order to make my copter smaller. My requirements is that it could operate with external NAV messages( Visodom etc) at near real time rate , about 20-30 Hz, and obviously had stable fast interface with a companion. What boards would you suggest me, dear experts? I can read of course about all options, but i haven’t practical experience anyway) I would like to listen experts opinion.
Thank you.