Mic Recommendation for Acoustic Upright Bass?

Just to be clear - I´m no expert on the subject, I just bang my guitars & shout a lot + we play some kind of rockabilly I guess.
Our bassplayer uses this system http://kksound.com/products/bassmasterrb.php , previous to that he used a Shadow-mic, I think it´s this one : https://shadowelectronics.com/collections/upright-bass-pickups/products/sh-951 which sounds fine, but the K&K-system gives you more options: fretboard/neck and bridge pickups & separate 3 band eq for both inside the preamp-box + it can be louder than the Shadow pickup.
There are other makers off course from David Gage, Schaller, Fishman and probably a lot of other makers.
 
If it´s for studio use Dave Darling´s answers here might be useful: https://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/101772-recording-upright-bass-rockabilly-hints-tricks.html

Thanks guys.  Great suggestions. That kksound stuff looks like it might be really cool for him.  I sent him the link for their site, and someone else responded with the same info.  (He had asked on FaceBook.)

Thanks.  The DPA was one of the first I found when I Googled and I told him that one as well.  I think he had so many friends respond with suggestions that the only problem he'll have now is deciding which one to choose.

personal taste, of course!
For pickups I like the K&K, just put their trio in my Santa Cruz dread and it sounds great. I seldom plug it in, so I wanted to keep it simple. K&K just seems to "get it" when it comes to simple pickups. I've not tried any of the other bass pickup systems, so I could be all wet.

For microphones, it depends on the musical setting, but mostly I use an RE-20, an MD-421, or lately a Royer R-101. I've also used a Fostex M88RP, a bit of an oddball, and it doesn't like every acoustic bass, but when it works it is pretty darned cool. If I had the budget I'd probably try a couple of the RCA clones, but I don't have the budget, so that's just an idea.

I've tried the AKG 414EB and C12A, and they were both a little too aggressive for my tastes. I've tried using one of them and a Royer R-101 and that was an interesting combination, very flexible at mixdown time. I've also tried both the Neumann TLM-193 (which works on almost anything) and a Shure KSM-32, but never found a sweet spot for either.

You can get a used RE-20 or MD-421 for a reasonable price on the usual auction sites, and that's where I'd start.