Local or map bound?

Until now I've only made maps using standard stuff in the editor.

The reason I don't use custom speech, tiles or models is that other players do not have the files. Am I right saying custom speech and models are merely local, and not saved in the map?

In order to create custom speech an existing's unit speech has to be overwritten in the entire game, like with starcraft, am I right? Or is it possible to make additional speech in one map only, saved within the w3m?

I like making maps for my friends, but they won't play it unless I only have to give the w3m (easily confused :p)

If you import the custom stuff into the map, like you would into an MPQ, it will work, as long as we aren't talking about datafiles. But...you have to keep under 4 MB. Sucks a lot.