Whats the best way to make available wiki entries in our internal Sharepoint
site on our external website?

Ideally I'd like to interface the two so that I can pull the wiki content out of
sharepoint and display it in the external site. Alternatively perhaps I'd
consider redesigning the sharepoint site in to the same look at feel as the
external site and then linking from the external to the internal wiki. However I
don't really know how far you can customise the look of sharepoint beyond the
basics of adding a company logo etc.

We use sharepoint mainly for file storage, but over the years it's grown to be
used for wiki how-tos etc for internal staff as well as the usual calendars etc.
We used to create each important wiki entry twice, once on sharepoint and once
on the external facing website for clients to see. However this just let to a
lot of work and eventually pages were appearing on one and not the other. What
I'm keen to do with our upcoming new site is to have one source for wiki content
but make it available to both external clients and internal staff, but in such a
way that each keeps the usual look and feel (external clients seeing our
site-branded content and internal staff seeing the usual sharepoint site).

Is anything like that possible ?