Acoustic purists move on - nothing to see here

I've decided to make a grunge acoustic guitar. It's gotta be cheap which is why I've decided to use the cheapest new guitar I can find. This is a Stagg SW201 see
http://www.dolphinmusic.co.uk/product/43832-stagg-sw201-dreadnought-acoustic-guitar-redburst.html#sterling_uk (If I'd bought it yesterday it would have been £40. Arrr... I just hate bookmarking stuff and then going back a few days later to find they've hiked up the price, don't you)
Anyhow... a P90 pick-up is what I want on it - see
http://thumbs2.ebaystatic.com/m/mHdnmyJwzbV04R2-ISm3uIw/140.jpg (It really is a P90 - a Kent Armstrong P90 in what they call a "retrofit" casing - makes it easier to mount.
This seems to have a one core wire with shield coming out from it.
To any of you with electronic pick-up knowledge... am I right in thinking that I just need to take the shield to the collar of a jack socket and the core to the centre? I know that this is obviously a passive set up and plan to use an ART preamp with it.
Am I also right in thinking that the distance that the pick-up is mounted from the strings is important? I plan to just experiment with the sound at different distances and positions and then screw in a piece of 1/2" thick plank to the inside of the guitar on which to mount the pick-up with shimmys to bring it to the best sounding level.
Is this insane?