[OJ1988]

Imo, you need good mids and highs on the front channel, good mids and highs on the rear, and some low end bass.

For me, I like 6.5"s in front, 3 ways or components, 3 way 6x9 in rear, and a single sub, 10" works well for all but the hardest hitting bass.

I run all mids and highs of a 4 channel amp and sub off a single amp.

Now, with your setup, 4 8's are going to give a lot of mid bass, not much low end, so you can supplement with some better highs. 6x9s in doors, and center high speakers will probably do well, if matched to amp.

You could add some kick panle mounted 6" but, I don't think you really need it.

But, I would not have recommended 4 8's, so if it is wow factor, add the 6" as well.