Good Replacement for stock C6 subs in door

[01c5z06]

What kind of subs would be acceptable to upgrade the stock in door sub speakers? I have the stock non-Bose setup and would like to upgrade my speakers without having to add a new amp. As I understand the are 3, 3 1/2", 2 10" subs in door and 2, 5 1/4 speakers in the system. Any recommendations would be very much appreciated.

[Dueysan]

I'm in the same boat. I've got a vert on order and listened to the blose system in a similiar car they had in stock.....it was pretty weak...want to keep car stock looking and plan on replacing all the speakers except the center channel (which I'll just disconnect) and ditching the Blose amps for aftermarket either a 4 channel and two channel or a larger 6 channel amp. Any experience with in door woofers would be especially appreciated....thinking about using some Polk 8" in place of the Blose 10" but I will need to check dimensions and make sure the polks aren't too deep. Anyone?