FWIW, "drilling" the guitar is inconsequential. All you're doing is making the strap end pin "screw hole" into a 1/2" hole to accomodate an output jack. And if you sell the guitar but want to
keep the pup (ok, and how many people
really do that?) all you do is buy a 1/2" endpin jack (say from StewMac or elsewhere for a couple o bucks) that fits the now-vacant 1/2" hole and has a standard strap button on the end: looks and functions 100% stock. One is
not marring or adversely altering a guitar in any way by adding a pup that is more "integrated" than a simple soundhole pup.
BTW, just adding in the above as an FYI. There are plenty of decent soundhole pups if that is your inclination. I've installed Fishmans and Baggs units on various friends' guitars over the years and they work/sound fine. What your tonal desires and/goals are is a highly personal matter so choose accordingly
Edward