Well, after a long time in the theoretical world, I decided it's time to see how APM works in reality, so I splashed some cash and ordered this and a bunch of other parts from Hobby King:
At this point, my MS Excel OCD set in and I felt the need to figure out how I could package everything and still achieve a good CoG position. Taking the front of the launch finger holes as the published "ideal" CoG starting position, and the nose of the fuselage as my zero moment reference, I weighed, measured and calculated* the following:
I was surpised that this arrangement seems to put the battery way out in front - much further forward than I anticipated, which will give me some good headroom to add other, lighter things further forward. I can also double the battery capacity moving the pack CoG back to 345mm, which might be a handy thing!
So, my initial spec will be as follows:
Motor: NTM Prop Drive 28-36 2200Kv
ESC: Turnigy AE-45A
Sensors: MT3329 GPS
MPXV7002DP Pitot-static IAS
MHC5843 remote Magetometer
LV-EZ0 Sonar Altimeter
Servos: HTX900 9g
Radio: Futaba R617FS decased
Battery: Zippy Compact 4S 25C 2200mAh
More to follow as the build progresses.
*after ripping all the stickers off...