Below are listed the US Carp tackle retailers that I am familiar with.

EuroTackle Nigel Griffin's company in Connecticut. A real class act.  I've purchased from Nigel and his service was excellent.  Carries the Gardner line of Carp tackle and Kevlite Rods. 

Specialist Angling Supplies USA Corp.  A company I have just recently become aware of, though I have yet to order anything from them.  They list a good looking inventory on their website, though all the special effects going between pages makes me nuts. SAS USA Corp. is located in Springfield, IL.

Wacker Bait and Tackle the US distributor for Pescaviva baits and Fox Tackle.  I have dealt personally with Paul Pezalla, the owner and can highly recommend his company for whatever you may need in the way of Carp tackle or baits.

Cabela's - Carries European style rods and Shimano Baitrunner Reels

Bass Pro Shop - Carries Shimano Baitrunner reels