The boards in High Speed use Molex .156" connectors.

http://www.bigdaddy-enterprises.com/electronics/e_connectors-156.htm

Ya, Big Daddy will have you covered.

greatplainselectronics.com, bigdaddy-enterprises.com, mouser.com, digikey.com

I really only replace any high current header pins and connectors, and the rest on an as-needed basis.

For each board, you can look at the parts list in the manual. Those will list the Williams parts numbers, and you can usually get a Molex part number from that.

But generally, for boards, you're looking at either .100" or .156" molex connectors and header pins. Some are friction lock connectors, some are not.

For plug & socket connections, most tend to be .084", although some can be .062" or .093".

https://www.greatplainselectronics.com/categories.asp?cat=35

These measurements are the "pitch" measurement for the connectors. In other words, the measurement between the center point of two pins. You will likely need digital calipers in order to measure this since they are only fractions of an inch.

Even though this particular size isn't used in pinball, this helps illustrate where to measure:
pcb-connector-pitch-size-.079 (resized).png

It will take a little while to get the hang of what sizes are which and what the molex part numbers are, but if you work with them often enough, you'll be able to recognize them by sight.

There's some good supplemental information here: http://www.pinrepair.com/connect/

Brownie point for ForceFlow for the detailed connector information.

Usually 18 for coils/flashers and power, 20 for switches and (usually) feature lamps.

Pins are cheap. Connector housings are not. I only replace those if I really have to. Partly because of the expense, and partly because some of them are starting to become scarce. As long as they aren't IDC connectors and as long as they aren't broken or burnt, they are still good.