I would suggest you save a little cash and go with standard HSS rather than the cobalt. Cobalt tools are good for SS, and can give a better finish, but unless your using a CNC machine the benefits are minimal. The cobalt drills are more brittle (as they are harder) which can be a down side if you slip up a little. The real advantage to the cobalt is that they can take a higher heat without loosing their hardness. This is something that shouldn't come up if your careful. I would recommend getting a few non-cobalt HSS drills, and one or two double sided #2 center-drills. Just go slow and keep things wet (with coolant, oil, or if need be spit)
I=V/R so R=V/I and V=I*R
P=V*I
(I=Amps, V=volts, P= power in watts, R=resistance in ohms)