no use a higher gauge then 8, 4 at minimum for power and ground wire. personally i would just buy a spool of 0- 4 gauge wire then some 10 and 16 gauge wire as well as the distribution block and necessary fuses, Ive found its cheaper to buy everything separately in bulk then to buy a kit which sometimes does not come with enough wire. make sure you ground both amps to the same spot with same gauge wire. also make sure you run the power cable from battery to amps on opposite sides of the vehicle than the signal wires(head unit to amps) use the 0-4 gauge for power and grounds, the 10 gauge for the 12 volt wire and wire from amp to subs, and the 16 for amp to speakers. it may cost more to buy it all separate in bulk up front but will definitely save you in the future if you find yourself needing it for something else. i find myself needing it alot since i hook up alot of mobile electronics for friends and such. most of this stuff can be found in good quality at a radio shack or similar electronic store.