Helicopter project

I'm officially getting the helicopter project off the ground (so to speak). The goal is to build an auto-stabilizing (via active electronic control) R/C helicopter. Or rather, since I plan to buy a 5-channel ready-to-fly helicopter, the goal is to build an electronic control system that will interface with the helicopter's existing actuators and radio  receiver. Some thoughts on various parts of the project:
Interfacing with the helicopter: For this, I really need to buy a helicopter and get access to an oscilloscope, but if it's anything like the R/C plane I'd played with, then it's all PWM servo control signals, which will be easy to work with. Helicopter should also have a 4.8V battery back for the control electronics, and/or a 3.3V regulator on board?
Sensors: SparkFun has a pretty nifty sensor: 3 axis accelerometer, 3 axis gyro, 3 axis magnetometer, and an ATmega328 chip w/ bootloader, all on a small 3.3V board. The only downside is that it's $125, but I guess you have to bite the bullet somewhere. These sensors are expensive and tend to come in hard-to-solder packages (where all the pins are on the bottom). Board printing is not too cheap (AP Circuits $20 for a small board + $40 shipping; ugh) and doing the board design and programming an on-board microcontroller...it's just too much for now.
The other option, though, is to get an Arduino (which I'll need anyways) and some accelerometer or gyro breakout boards: they're not much more expensive than the sensors alone from DigiKey or Mouser, and it saves a lot of trouble. They have analog output, which is easy to read but prone to noise. (some might have PWM? Will have to look again to check for serial).


Next step: Well, unfortunately SparkFun is out of 3.3V Arduino Pro's and FTDI USB-Serial breakouts, so I'll just have to wait on that. Looks like buying the helicopter is the next step...