Hardly H-Bridges are single channel , atleast the most popular like L293D or this SN44 series are all dual channel even the small SOP-8 packaged H-Bridges are 2channel, just go for that chip on sparkfun and just connect their channels to double the current flow capacity through the H-Bridge and believe me you have to do as im saying because these motors take a lot of amperage in current and the H-Bridges you are looking at are entry level small one's which have low current flow capacity.
Or, make out your own H-Bridge http://www.bristolwatch.com/ele/h_bridge.htm with power mosfets.