list the specs of the amp and if it's rated stable at 2 ohms bridged.
list the specs of the sub, are they single or dual voice coil?
if the amp is stable at 2ohms, wire the subs in parallel to show a 2ohm load, bridge the amp, and this is your best setup, since the subs will be twice as efficient (in theory) running at 2ohms resistance, rather than 4ohms.