Trapps, why do you want rid of your sub? Could it be your box is a little big?
Your equipment is all top notch. I would not go with 4 8's. I would go with 2 8's or 2 10's for sq purpose. I have 2 8's and they are solid!
Your amps and speakers are fine too. I think your problem might be in your x-over setting.
These are some of my choices.
8" subs Crystal mobile (must call directly, limited) PPI PRO8 10" subs Nakamichi SP-W104 Nakamichi SP-W100 Crystal CSE 10.4 Crystal CMP 10 PPI Pro10 These are only subs that I have heard and can suggest. As you know without the proper install they will all sound like a$$. Good luck.
Personally I think your system has great potential but may just need some adjustment. Listen to a friends system and compare. BTW, what HU do you have?
Cheers
