Here are the differences:
Sure Power 1314A: Single sensing, closed current 750mA, Cranking Amps 400A, Continuous Amps 100A
http://www.ase-supply.com/v/vspfiles/downloadables/1314-1315.pdf
Blue Sea 7611: Dual sensing, closed current ~100mA (measured), Cranking Amps > 210A, Continuous Amps 120A...