Commando Archive

Just wanted to get some feedback on which line in commando to take. I will be extremely limited in the commando line considering i can only fill in oneline of the tree, but to three boxes. I just thought it would be cool to have the ability to pull out a heavy weapon in the few situations I would need them. (I.E against instillations and heavy armor) In that case what tree would yousuggest I take?

Thanks