Bill. If you can't see videos in the youtube links I think you need to scan your computer for virus/adware.
To the stabilizing stuff. Focal point is Patrik's site.
http://fotoflygarn.blogspot.se/2012/03/how-to-setup-multiwii-airplane-same.html He ported the software to be able to run airplanes applications. It's originally written for those multicopters. In short it's a 3 axis stabilization which is programmable in all kind of ways, PID based. A similar commercial is about 100-150 US $ The only drawback I have found compared with a commercial is there is no potentiometers to easily adjust the ratings at the field. However there is an Android app which together with a bluetooth dongle can do much more an are suited for the field as it's fully mobile.
What you need to buy:
1: The processor itself. There are a lot of sources where to purchase it, taking this as an example as I bought several from this guy without issues:
http://www.ebay.com/itm/5V-16MHz-ATmega328P-AU-Pro-Mini-Support-Arduino-Processing-Language-/130701734911?pt=LH_DefaultDomain_0&hash=item1e6e6e33ff2: 3 axix gyro, picked from a Wii motion plus controller. There is a lot of Wii plus controllers out there, mostly clones. Some of the clones will work, some not (The ones from DealExtream will NOT work for example). Therefore it's best hitting an original. Ebay, or amazon are good sources. Although the seller write "original" in the advertise that doesn't have to be true. I bought the last batch from a seller in US to make sure it was genuine as I was cheated once to much. As a last resort just convince your mate he/she should not play those stupid games anyway and steal it. What's needed is just the small add-on and not the complete controller. A pic of just the add-on here. (can't tell for sure this guy is actually selling originals although claiming they are):
http://www.ebay.com/itm/Nintendo-Wii-Original-Motion-Plus-Sensor-Adapter-for-Nintendo-Wii-Remote-White-/290659102186?pt=Video_Games_Accessories&hash=item43aca1edea3: A one time investment is a serial to USB converter. I say one time as I use one of the above set for each of my plane I stabilize. It's kind of time consuming to re-program for a different airplane and they are cheap..
As said, Arduino stuff is easy to get from all different places but this is an example of the converter:
http://www.ebay.com/itm/FT232RL-USB-to-Serial-adapter-module-USB-TO-232-for-Arduino-download-cable-/180871619690?pt=LH_DefaultDomain_0&hash=item2a1cc9e46a4: Optional. A bluetooth dongle to be able to program at the field. You could do with just this one but I very much recommend the serial to USB as it will definitely simplify things when getting the first stabilizer up and running. The bluetooth app doesn't feel that stable yet and is still undergoing a lot of development. I would say, get it when you have the first stabilizer up and running.
5: Cables and connectors. Then depending on plane and situation a "shield" or "breakout" board can also be used. It will take more space though. All mine, 10 so far, stabilizers is just built with connectors. And the motion wii ontop of the Arduini with some foam in between and in the bottom. Tape to keep it together and velcro to fit it into the plane.
Now, I guess there will be questions around this, but you are welcome and I will try to answer as best I can. The links on Patrick's site will be useful as well. There is a long, and unfortunately written in swedish, thread where the plane porting basically was borne and I did my trials and errors and Patrick was trying to help out. But if anyone happen to manage reading swedish is located here:
http://www.rcflyg.se/forum/showthread.php/31350-G%C3%A5r-det-att-ha-multiwii-i-flygplanThe stuff to the left in this pic is my first "prototype" stabilizer in the AXN, the very same as in the video some entries above.
http://www.rcflyg.se/forum/attachment.php?attachmentid=26864&d=1330183584/Håkan