Thanks all. I think LED battens will work best for my circumstances – panels would inevitably get in the way (or, more likely, get damaged) when hauling stuff down from above the rafters.
I put some Pro-Elec (Farnell own brand) ones in earlier this year: https://cpc.farnell.com/c/electrical-lighting/lighting/commercial-lighting/led-batten-fittings?brand=pro-elec
They’re very lightweight and flimsy, but they’re stuck to the ceiling, so they don’t really need to be heavy duty. Otherwise really impressive and ridiculously cheap.
@thenorthwind, do those have diffusers? (or, do you find they’re good or bad for glare, or indifferent?). They’re REALLY cheap even compared to the Amazon ones posted above. I used LAP (or similar from Screwfix) undercounter in my kitchen which are great but weren’t the cheapest. I could go utterly wild in the garage with those CPC ones at that price.
I’m thinking multiple smaller units rather than only a couple of big ones: more light sources from different directions to minimise shadows. Currently have 12 x 4w/230lm spots, so using 6 x 8w/800lm ones in the same locations as my current lights would be a big increase in output and hopefully less glare.