I purchased a neat little pickup on eBay which I've just tested in my Vantage VW150, and I'm really impressed!
It's made by ARTEC and is not only well made but beautiful as well! You can look it up on eBay or check the seller's web site for pix and options:
http://guitarfuel.com/Sound_Hole_Pickups.phpIn a nutshell, this Korean made product is an actual humbucker not a piezo or single coil, and it's potted, available in two versions, with and without pole pieces, and in a variety of gorgeous woods and several pin connectors. I got one in Bubinga with an outside connector but you can get an end pin replacement if you want to install it more permanently. My original thought was to swap it between my Vantage and the el Degas Dove. But it took a bit more fiddling to get it in than I was prepared for so it may end up staying in awhile.
This thing is terrific (not that I have anything similar to compare it to) but to my ears it's way more natural sounding than my 3 piezo equipped guitars in the stable. Honestly, the sound is warm and natural and doesn't seem to add any colouration, and, it's dead quiet! You don't even know it's there. As I say, I'm very impressed! I put the meter on it before soldering her up and it tested at a respectable 6.25 K.
I'm also impressed with the price of USD$34.95, but I happened to get them when they had a sale so I got it for $29.95 which nicely covered the shipping of $5! Worth checking out, and it won't break the bank!