Hitec makes a continuous rotation servo, so does Parallax... Hoverer, the servos here in the ez robot store are just as good and they can handle 7.4v....You may have to go to a geared DC motor to get the kind of torque you are after, though....

Goto www.servocity.com. .....

Other than dynamixel, you won't find any better servo than ours. The servos we sell are modified for even higher quality than the standard version.

I don't see where you sell just a servo. Everything I see has an EZ Bit with it. I also don't see any micro servos or heavy duty ones. I am in need of all three but delivery is over a month or maybe even more. I would really like to get started before that. Am I missing something.

servos

Thanks @d.cochran.

@DJSures: there's only two type of servo in EZstore if there is 25kg-cm i wont go to other store...

None of the stores servos produce that much torque.... This one does but it is quarter scale size ...Quater scale servo I will say it again, use a geared DC motor instead. They are much better suited for drive wheels.... Servos were originally never meant for 360 deg rotation.... As drive wheels they won't last as long as geared DC motors will....

EDIT the link above is for a giant sized servo not quarter sized....

Also try Pololu.com I think I rememberseeing a serious servo, that will run off of 12VDC but can lift up to 200lbs. Im sure thats a bit of overkill, but they do have a selection of others. I myself, might at some point get one of those monster servos, I have an arm design that is in need of lifting at least a 150lb human with ease (for a medical design).