Shadow pickups are
ok, but I would recommend a Fishman over them anyday. Is there any reason why you're opting for a sound hole mounted coil rather than a saddle mounted one? I have two guitars, one with each, and the saddle mounted one does sound infinitely better in my opinion, but they both offer very distinctly different sounds. Also, I would recommend, almost to the point of saying don't buy one unless, you buy a pickup that has a mic as well.
I have this pickup in my Taylor:
http://www.guitar.co.uk/extras/pick..._earth_single_coil_acoustic_sound_hole_pickup
And it's a great, great pickup. But it doesn't give a sound that's even close to sounding natural and depending on what you're after, that maybe something of a problem.
I also have a Maton EBG808TE (the guitar that Tommy Emmanuel uses, if you know him) and it is a different animal when plugged in. It has six piezo, undersaddle pickups (one per string) and a condenser microphone mounted at the edge of the soundhole. You cannot even compare the two when looking for a big, natural sound. In all fairness, the Maton sports (in my opinion), the best acoustic guitar pickup in the world, bar none. But the principle of a coil and a mic sounding better than a coil, remains.
I would recommend you purchase something like this, budget allowing:
http://www.imuso.co.uk/Accessories/...Pickup-Preamp-Narrow?utm_source=googleproduct
or
http://www.soundslive.co.uk/product.asp?id=1818
Good magnetic acoustic guitar pickups do sound great, but for me, the Piezoelectric pickup is in a league of it's own. Upon rereading the post, I've realised that this is a fairly useless post with regard to your actual question, but all the same, these are things that one really needs to consider before purchasing an acoustic guitar pickup.
The pickup you linked is alright, but I would always recommend industry leading brands such as Fishman or L.R. Braggs.
Have a look on here to get a taste of what different pickups sound like:
http://www.dougyoungguitar.com/pickuptests/
Remember though, nothing like this will ever give you an accurate idea of what they'll sound like when you get it home and plug it in.