Hi Dunny, welcome to the forums! Good to have another real-world pilot join the craziness here.

You've already got some good advice, so I won't repeat a bunch of stuff. I just wanted to throw out the idea of using a real cockpit instead of building one from scratch. I went the scratch-built route initially, and that sim is still running and is fine, but I later got the front of a Sabreliner and it's 100x a better deal. The cockpit build was an enormous amount of time and effort....time and effort that could have been better spent refreshing a real cockpit, writing code, interfacing gauges, etc. Sticking a real plane in your garage/house/neighbor's driveway may seem extreme at first, but it's really not. Old fuselages and cockpits, especially for small aircraft like the 172, can be had for next to nothing if you are patient and nosy. I see you're in the UK, I know of quite a few guys in Europe who have managed to get their hands on a real cockpit.

Here's my current site for some inspiration (it's sorta set up like a commercial deal, but it's not..yet):

http://www.baileyjets.com/

Matt