Tools needed to finish rebuilding my engine

My 1st gear is out on my 2000 Honda Foreman 450 ES and I have a guy at my work who has gotten the bike down to the clutch so far. I figured out the clutch puller is $100 (unless he is willing to try a couple suggestions I saw on here last night), so I wanted to know what other tools are mandatory to finish the job. My friend repairs/rebuilds aircraft engines, so he has access to about any tool possible and things he can fabricate a tool for most anything, so is there any other major tools necessary? I will buy the tool for him if that is the smart thing to do, but I would rather order all the tools necessary at once so we can get this thing running again. Any help is appreciated.