tbh with the 4ish weeks wait, it is what it is, retrofit labs seem to have a good rep and i can wait,
like you i suspect they are all "MiC" and of about the same quality, having bought far more from china than the uk for a couple of hobbys alibabba isnt an unknown, ill stick with retrolabs , they appear to have decent customer contact (so far), so "if",, then there maybe chance to Telephone and talk rather than,,well the CS i have had from Some china vendors ,,, "customer Scare" more than service,,,
But that listings photos have shown me what the bi-xenon filter thingy is , and the small electro magnet to twiddle (adjust) the shutter,, thats SO getting wired to the highbeams when they arrive and get fitted.