I'd like to do some M5 thread tapping with my cordless drill. It has the option to gear-down for slower, high torque applications so seem suitable.

In this case do you think it is better to use a spiral tap bit typical for automated tapping, or just go with the usual hand-tapping bits?

If someone is kind enough to send me a little block of steel (see classifieds), I plan to make a guide to start the thread at a nice right-angle.