I use the race MSD7AL boxes on most of my race and street cars, I bought the cheapo(under $50.00 at Summit ) Flaming River battery powered timing light to use on them As far as a piston stop you can make one out of a old spark plug, knock the center porcelyn and main conductor out of it with a punch, remove the ground strap and insert a bolt(weld in place if yuo want or use alltherad with two nuts to hold in place) to act as the piston stop You cane buy them at most tool places also, I bought mine from Cheif Aircraft supply in Grants Pass, Oregon years ago when I owned and flew my airplane Make sure you get one for both 14 and 18 MM for airplane and car use AKA you need the 14MM stop