2 sets of tweet is not overkill - its just horrible for imaging.
Buy 1 set of comps with the money u planned on using for the 2 sets. Bi-amp them.
Get an aftermarket setup.
An 8" Alpine type R will make you plenty happy if you planned on keeping the factory sub in the first place (its 100000x better at least).
Here is a link to my build log (almost complete) if you are curious...