I looked at the spaghetti menders blocks at the IHRA national in Tulsa. Talked to the guys and they can custom build any block you need. Really nice stuff. Dob't know that it is any better that the painless I haven't used either one. I have wired quite a few cars and usually make up my own blocks. The spaghetti menders block looked to be propietary to their switch panel by using a parallel cable to do the hookup.
K&R also has a nice relay panel that you might check out.
Curtis