I have a map i'm starting that needs ammo droids that only give ammo for one weapon. Is this possible? I looked at the .odf but i couldn't find anything.

I don't know of any good way to do that. If it helps any, you can link weapons to make them share the same ammo.

There is some crazy lua coding way that might work, but it would be SP only and it would change the ammo for everyone of that class (meaning only one unit per playable class). Its about the worst possible way to do it.