Hello, I just installed a B-band A2 in one of my guitars and am very happy with it, it is kinda of a tricky one to install and they are a little more spendy than some. I paid about $200. They have an undersaddle pickup and an ast pickup, you can balance both pickups and volume control also.
I also have a LR Baggs I-Beam in one of my guitars and it is alot less money and more basic. It has a volume control and it's about a $90. pickup.
Neither require cutting any holes in your guitar for batteries, the batteries velcro on the inside, the only drilling is where you remove your strap pin and your input for your 1/4'' cable hooks up.
I am going to replace my I-Beam with a B-band A2 after I have used the new one awhile I like the mix you get and lots of volume and no acoustic quack of some pickups.Very authentic acoustic sound.
Later Wayne P
Later, Wayne P