Well just an update about the conversion...everything's so far going OK, except the 2-in-1 burned out somehow. I was testing the main motor for a while and then the main motor got stock on full throttle, no throttle adjustments at TX did anything. Unplugging unit from receiver didn't help either, looks like something shorted in the main motor speed control, because the tail motor and the LEDs and BEC still work fine. The unit did get hot though, although it SHOULD be able to take a LiPo. I'm getting it exchanged at the hobby shop tomorrow and they'll send it back to Horizon, and this time I bought a $4 XPS speed control heatsink (speed control used in the RC18t 1/18th scale R/C car) and I'll stick that to the side. Since the receiver I'm using is long and I don't want or need to spend $50 on a a micro receiver, I bought some balsa wood and CA-ed it to the top of the receiver mount plate, extending it an inch or so. The receiver fits nicely with enough room to remove and plug in servo plugs without removing receiver. However, the receiver sticks out too far and bumps into the top of the canopy, so I cut an opening (cut is the wrong word, more like bashed, I'll get a new canopy soon and do a better job on that after I'm done prototyping), so the crystal and the front of the receiver protrude a few mm, no biggie. Also the opening should get enough airflow going over the heatsink of the 2-in-1 and keep it cool. I'm mounting the 2-in-1 on the other side of the receiver, which is separated by a vertical balsa slab and mounted against that. The gyro has a very nice spot attached to the back of the two rear servos, where it fits perfectly and works great (you need to position the gyro so that it is in line with the axis it will be rotating on, so I couldn't put it flat on something, it needed to be vertical). Rudder test showed that the gyro works very well, adjusting the tail rotor speed as I yawed the helicopter left and right.

So far so good, all that's left is to exchange my 2-in-1 tomorrow and mount it and I should be GOOD TO GO! Will take photos then.

If everything works out great, then I will write up a simple tutorial. It's really not that hard on concept, the hard part is just deciding where to mount everything because there's not a lot of space, and routing the wiring so that it doesn't hit the main gear or block any servo movement.