COD2 will always download what the client needs. Because there are image and menu files you require, it does indeed require a download. This is unavoidable because Powerserver is not a server-side-only mod.
It is possible to split the mod into those parts which can remain purely server-side, and those that require a client download. I'll split it for you, and while I am at it, add the anti-name changer mod as well.