First- You can mic your acoustic and play through a pa or your amp if you have the equipment. Or even stereo speakers if you have a 4 track!!!
Second- Single coil pickup, usually cheaper than humbucker, made by many companys, the quality depends on the company your buy it from. Check out fishman(rare earth), seymour duncan, and Martin. It all depends on what you want to spend.
Humbucker- Usually a little more than the single coil, fishman is suppose to make a good humbucker, the rare earth series. Less hum noise than single coil hence quieter operation.
Pickup and mic combo- The mag mic by Seymour duncan (~$300) combines a pickup with a small mic that sits inside(or just outside) of the soundhole. These are suppose to be the hightest quality and most expensive ways to amplify an acoustic. Fishman makes one called the fishman rare earth blend soundhole pickup.
I think a good thing the look at is the quality of your guitar as well. Some of the more expensive pickups are expensive becasue they add no tonal qualities to your guitar it basically justs adds volume to the existing tone within your guitar. Thats great if you have a nice or good sounding guitar. If you dont then dont spend big bucks to reproduce a guitars tone that sucks. Follow my drift, your options are endless so its up to you. I just wouldnt spend more on a mic than the guitar costs.
What kind of guitar do you have?
Thomyorke575