Ok, let's assume that you have a decent PA with tops and a sub. If you have a 'vocal only' PA, then there's no point in trying to put the drums through it.
This mic set is very usable (I have some experience of it), and not too expensive. I would keep away from the uber-cheap kits, as they tend to be more trouble than they're worth.
Amazon.com: CAD Premium 7-Piece Drum Microphone Pack: Musical Instruments
Bear in mind that adding drums to the PA increases the demands of whoever mixes the show; a longer soundcheck will be required to make the band sound 'right', and the person mixing will need some skill with an EQ to make sure everything works together and nothing sticks out.
If this all sounds a bit much, you can get away with mic'ing just the kick. There are lots of options for a kick mic, depending on budget and what kind of sound you want.