That nail gun sounds like a good purchase.
On the chain saw... they can be extremely dangerous!
If you already know how to safely use one that's great, but if this is a tool that you have little or no experience with then training is key. Hands on with someone who is skilled in chain saw use is best, but if you don't have access to anyone like that then YouTube can be very helpful. If you like I can post up some links to some videos that may be helpful.