I am in the process of buying a Mercedes Sprinter mwb and am wondering how best to set it up as a small, compact motorhome.

You're welcome, there's heaps on there, I hope this helps: https://www.youtube.com/results?search_query=mercedes+sprinter+van+conversion

Here's a time lapse of a Merc sprinter conversion, this might give you some ideas.

Hmmm theres many ways to answer this question. Have you checked out any YouTube videos on the subject?