Best two amps to bridge for subwoofers.

Can anyone help? I'm looking for two reasonably priced amps ($300-$500) each that I can bridge to run my two Citation 7.4 THX Subs. Looking at Adcom 555 II. Already using Carver 500xTHX. Should I buy another and use them in a bridged mode? Can these subs handle that kind of power? Thank you for your help!!!!