In addition I would recommend a set of tiny wrenches or hex sockets. There's a lot of hex nuts in a heli that need to be held or twisted during assembly/disassembly. A nice to have item is a regular/metric ruler. However, I myself prefer the electronic calipers that I got for $29 from Harbor Freight. This item helps you set up rod lengths, and it helps in identifying the incredible number of screws that are used in a heli.

As for field tools, you will also need a glow-plug wrench.