Way back in 2013, I ordered a great P60 drop-in from Int’l Outdoor store. For a long time, there was a menu tool where you picked/customized a limited numbers of options…reflector smoothness, number of modes, LED type and tint. Then they would build a P60 drop-in per your specs. It was great. Is anybody offering that service anymore?
Just a footnote, The Drop in I ordered in 2013 was an XM-L2, 4 mode, orange peel, with 3.04 amp driver. And it has served very well, inside a Solarforce L2P host, as an EDC for many years. I’d like to buy something equivalent today, just with a more modern LED.
The only shop that still does a variety of P60 dropins (and a nice host too btw) currently, by my knowledge, is kaidomain.com. He may not build them to specs for you (or on the other hand he may, he is BanL on BLF, you could try a PM) but he does have a good choice.
I have both Lumens Factory, Malkoff and Customlites P60s in some various mounted lights. Can’t go wrong with any but I’d lean towards the Malkoff line fore sure, with a not terribly close second place to Lumens Factory (they are still great but malkoff just exudes quality).
No experience with the KD options but have heard good things in the past. Still, I wouldn’t put them anywhere near the above mentioned options.