I would aim for the 219c, side effects its the hottest running....................none of them can run long anyway, so might as well get the colour temp you like!. My 219c is a clean white beam, thats what i wanted and got! Clips wise, the better option is probably oveready or darksucks, just dremmel the inner part a little to fit over threads. Yes a $25 clip, if you like the light(pretty much guaranteed) then its worth it to secure the light and imo looks far nicer than the cheap clip on clips. Subjective!
As for less bright................3800lm is hardly dim. Will not throw quite as far as the HI versionn but reaches out enough for most uses. Maybe a few 100lm less.............in the scheme of things it would not be a deciding factor for me. Colour temp/tint is what you will be looking at , the 219c is nice all the way through the levels.
I got the 219c, for the wider flood and the price and color.