I had a look about for alternative brands of brush cutter that would drive the expand-it accessories from the ryobi. There were a few, but none compelling; Husqvarna do some - but very pricey and not that readily available. McCollouch seem to do one - but that looks very much like a badge engineered ryobi or similar. The Makita split shaft models apparently don't fit. Which brought me back to another ryobi.
I was contemplating something similar to what I had (30cc 2 stroke) which going to cost about £93, when I noticed that Makro had these 4 stroke ones at £89+VAT:
Seems to start nice an easily, but I shall report back once it has had a decent work out.