Sorry I didn't see this till just now. Looks like you posted this on Saturday? On Saturday I was replacing fuel lines on my truck. Thjen went drove her to a local car show... no time for the forum...
What are you working on?
What type of work do you do or plan on doing?
Generic answer is stick with 7" pads and smaller. Flex says you can use up to 8" diameter pads but there's a lot of 6.5" and 7.5" pad options in both foam and fiber/wool.