Cool! I stumbled across some high power UVA COBS on eBay yesterday. These claim up to 100W in the UVA 395nm 400nm range but I would suspect they spectrum will be at least a little fuzzier than one pure wavelength, especially given they are cheap Chinese units, in our case this is a benefit right?. I think these lights are used for curing certain plastics so it may be that they are becoming commodity? Anyway, they seem to becoming much cheaper than they have been, especially in the UVA range. UV LED's, especially in B/C have been expensive, inefficient and reasonably short lived I think, so this has made them impracticable for anyone but the obsessives.
I have also read varying accounts of UVC increasing trichome coverage and THC levels, some of it even well documented, but after looking into it, it seemed reptile UVB/UVC bulbs were still the only real practical solution, and well to be honest that sounded like a clusterfk that was more effort than my lazy ass could be bothered with. If UVA has similar benefits as well, then I'll be really interested to see what your experiment turns up.