How far from standard is it and how close to stock do you want to be?
Richh’s bike seems to be a great starting point to achieving your goal and apart from the obvious original exhaust pipes it is achievable at (in my opinion) reasonable rates.
I know Richh quite well I have no reason to doubt the standard of his work.
I would suggest to not set your sights to high as there is very little here in the UK that I would describe as stock however there is very little we can’t do. Remember we are here to help but it is your call.