Hi Gordo,
It's a good question, undoubtedly you need to consider whether you actually want to be an instructor, the difference between going through the motions because you want to fly jets or turbo props and doing it because you enjoy it is enormous - you probably don't know for sure either way at the moment but the idea is almost certainly attractive. Take it seriously though because just going through the motions is deeply unfair for the students you fly with, so you really do need to want to do it.
Living in East Kilbride puts you a wee bit away from the busier schools so travelling to lessons may be something to consider.
That said, Cumbernauld are often looking for instructors and you may fit the bill. Allan Falconer is the man to speak to, although he does run both the schools at PTH and Cumbernauld and has a vested interest, so he will undoubtedly be positive but generally I've found him to be a straight shooter. Get him to introduce you to a few of his more seasoned instructors, or even the ones who work for an airline and still instruct part time - the worst that will happen is that you drink a lot of tea but the guys are always happy to talk to you.
From the tone of your post, you're either a PPL or you're training towards a PPL.
Certainly becoming an instructor with a PPL and get paid for it is now possible but in reality the amount of time and work you need to put in, you may as well do the ATPL Theory (as the instructor theory is about the same) and CPL course if you have definitely decided to become a professional.
So if you do decide to be an instructor, I think you'd not be doing yourself any favours by just doing the instructor course and the Instructor exams.
Hopefully my babbling makes some sense. Feel free to PM me if you want to chat more.