Guys, be careful when pushing a PSU > 80% of its rating.  It could shorten its lifespan and possibly short out and endanger the equipment it's hooked up to.

In any event, I've used all Corsair CS750 and CX750's - both modular and not - until this last trip to Best Buy which was out of them.  I picked up an EVGA 600w single 12v rail unit (Bronze rating) that seems to be working just fine powering one S1.  The only problem with this EVGA power supply are the power connectors.  They are *thisclose* to being too short.  The Corsair power supply cables easily traverse the distance between the Ant S1's power connectors, both in the stock configuration and when the blades are turned outward.  I've also just picked up a Thermaltake 800w single rail PSU and will be trying it out when my new S1 arrives that I ordered from NinjaTech last Monday night.