Just found this thread. I have the 81 inch BH Shrike and have just completed it with full electric (motors and gear). I used the E-Flite 46 motors and 60amp speed controllers. I replaced the retracts with electric (this was fun!) once I found a set that had rotating mains and could handle this size plane. Mouting the motors took a little searching because using the stock mount that comes with the E-Flite 46 motors, you need to bring it out 1.75 inches. I found some standoffs at Horizon Hobby for an Evolution engine that were exactly 1.75 inches. The great thing is that using this setup, two of the 4 holes already drilled in the firewalls matched up perfectly and centered the motor right where it needed to be. Just need to drill the other two holes.
The electric gear I used was from www.parkrcmodels.com
1 x RC Lander Large Scale Rotating Electric Retract Landing Gear (RCLMERROT) = $149.95
Main Rotation Choice 90 degree Rotating Mains
Rotating Retract Options Standard - 2 Rotating Mains with Std Nose Gear Base
I had to do some internal work to build up the platform inside the wing to accept the two main gear mounts but after doing that, they fit pretty well. I can give more details if anyone would like.
At this point, the plane is ready to fly but has not had its first jump into the air. Hope to do this in the next couple weeks. Ohio weather is pretty unpredictable at this time of year so who knows when it will be good enough for a first flight.