Thanks so much for the suggestions. I own a Stirio but have rather outgrown it now. Those kind of tools are fine for soup etc, but a Turkish Delight mixture is incredibly thick (traditional recipes use cornstarch rather than gelatin for the thickening/setting) and Stirio's motor just isn't powerful enough to handle it for more than a few minutes.
It also needs to be stirred much faster. Here's industry-scale Turkish Delight in action:
I'm kind of inbetween the home cook and commercial stage. I would like to start producing it in larger batches (3 or 4 litres at a time) but am working in a domestic kitchen.
There doesn't seem to be anything between doing it by hand or investing in huge, professional, industrial-size machines. Maybe the only solution is to look into customising a stand mixer and allowing a heat-source underneath?