These are very realistic pilot action figures I have found to be the best to build from.  They have a broad chest area making it easy to install standard servos.  Getting multiple heads to fit this pilot are easy.
Arms have many positions for placement.

Click-  How to build Pilot

Other parts needed to build:
2-   Low Profile Servos
1-   Micro Switch
12- Small 1cm/ 3/8" Screws
1- Bag of 1/4oz lead fishing weights