IMHO it's worth getting pre-fab daisy chains with insulating covers from Paradise.
- Red 0.250" 30 connection daisy chain
here - Black 0.250" 30 connection daisy chain
here - Red/black 0.250" 14 button LED harness
hereBuying one of each gives you 42 or 43 connections (14 on LED harness + 30 on daisy chain - 1 or 2 to connect the LED harness to the daisy chain)
Each daisy-chain segment is 6".
Check how many unused terminals you will have between clusters of buttons (3 in pic below) to ensure that the harnesses will reach all the buttons.
Scott