source for switching dc-dc step down converter?

I'm looking for a 12v to 7.2V (8v ok), 3A dc-dc converter - end product. I
don't mind soldering on input/output cables but want to minimize the time
modifying/building it.

The usage - have a camera flash's external power pack that has a 6x NiCd
battery pack that is aging. I want to power this unit with cheap and large
capacity 12V SLA battery. Why 12V? They are easy to find and cheap, and I
already have smart charger for 12V SLA. An in an emergency, I can yank the
battery from my motorcycle.

I would like to get a switching converter, meaning higher than 90%
efficiency and not much generated heat.

Could someone point me to a good online store to buy this kind of stuff?

I've been using google/froogle to look but has not found many relavent hits.


.

Loading