file size nightmares

hope someone can help with this.

I am having some trouble with file sizes:

what is the best size for a single movie?
how can you reduce the filesize once the build is complete?

I have a complicated file involving a county map of the uk, I have simplified it so there are less nodes to redraw each time but the file size is still too big, it is for a database search so it must be at the most 100k, each region has been split into one button (so it pops out once clicked) then it is subdivided into counties (another huge set of buttons) each county button contains a list of the major towns within that county from which the search is devised.

any suggestions?
I have used movie clips for the pop outs (which interact with the main timeline using tell target) so the frame usage is down to like 25 or so but this isn't having any effect on the file size.

Any suggestions

thanks in advance
stickygoblin