I have added the Music Maker cart to my list of options. A Rike caps upgrade will be considered once I know what sort of price range we are speaking about. As for the SUT/headamp suggestion, I have a rather impressive list of candidates that all hover around the 6-700£ price mark:

A Danish producer of a hand-wound SUT that emulates the Tribute SUT
A Silk Step up transformer from Thailand
Haufe t890 or another Haufe transformer
Lundahl transformers by many producers
Arkless headamp