Nice purchase, looks a good base and getting belts done before you even get it is ideal, piece of mind!
Presume you are chap on Facebook groups too who has his answer for carbon (carbon skins) and wheel refurb (snappy)? I have used both those for my stuff and wouldn't use anyone else, both offer great services at fair prices and superb results. both provide work second to none ime
Trendlines and leather rears work well, I have that setup in both my cars. I love the trendlines, many think they offer less support and comfort than stock seats but for me they are much better. I cover 15k+ a year and long commutes sometimes too and never fatigue despite pushing on towards 40 now.
Top inlet comes off easily enough, just be methodical and ensure when you refit you don't clamp or catch the HT leads as it can kill them and cause a misfire. I painted my top inlet recently with some aluminium look paint, I didn't actually take any pics and haven't even looked since but think it came out okay. Other car I had them vapour blasted which puts them back to pretty much factory finish, however needs to be maintained thereafter unlike paint. I also had my paint guy paint me an engine cover as I painted one myself and it was a bit,,,,rustic!
Anyway, enjoy the car, you must be getting giddy now like a kid at Christmas!