I actually believe that the Bellagio and Wynn both have 25K chips. My feeling on it is that I want them for my tourney set, so I did the chip mock up for them. You may not want it for your personal set, but I feel as though if I'm going to go through the cost, setup and effort to do a totally custom set, I'm going to get all that I could ever need in any type game. I want (in larger tourneys) to be able to duplicate what the WSOP does for their higher chip count, but need to stop somewhere, so I chose 25K. I'm also considering doing some 3's, 6's or 10's. (9/18, 6/12 - 12/24 and 10/20)
Getting started, I'll get set up with 1's though 1000's, much like my JB set now and add / expand on it when time / expenses allow.
As chipcos are very nice, I will not go with them as I want a clay chip, rather than a ceramic chip. I also don't care how chipcos wear the white outer ring on them after a fair amount of play. ASM is who I will likely go with. They have the mold I want and I've seen many other custom chips they have done which all turned out very very nice. Their prices are also very reasonable for a custom chip.