Glad to be able to help.... Oh, and you can use that same method to figure out waste spark firing groups on any motor regardless of the number of cylinders. Just remember, split the firing order in half and the first half of the firing order goes on top and the second half goes on bottom and the vertical colums are the paired groups.....
As for the suppressors, typically no, they are not needed but if its a street car, I would use them as electrical noise can reek havic on sensitive electronics..... Me personally, I always use them unless its a carberated race engine, but thats just me.....