NOTE: you will need to run a soldered wire from the middle lead of the lock switch area on the underside of the Home panel board (sorry, I don’t have a pic to visualize this for you) to serve as the ground connections for both the start and select buttons. The Round 2 has this functionality on-board as “KGND,” though the Round 1 does not.
NOTE: i had previously wired the LS/DP/RS incorrectly to the Brook UFB. I have since corrected it. See the photo for details on proper connection:
Agetech Dreamcast PCB is your #1 choice as it has VMU connector but they are harder to get
The MC Cthulhu is a really good 2nd choice, its one con for Dreamcast is the lack of VMU interface.