Heads-up on some of the PCBs listed here:
- The GMMK one has a bunch of features but it also doesn't have holes for PCB-mount switch legs, so it does require some mangling of switches. I haven't looked at the PCB too closely but I'm willing to bet it's an autoroute job as well
- The C3 PCBs (and a number of others on the TKL list) don't support QMK if that's a thing you need
All in all the h87 (and maybe the h88) are probably the ones most worth designing around: they adhere to a size/positioning standard that is common (across many of the boards in the list redbanshee linked), they're regularly-available, and they're designed/produced by a community member (hiney) who is very communicative/easy to contact.