With a TCR I think you'd need to try and get it in the Pure Grey special paint for it to stand out from the crowd, given how similar it still is to the normal GTI PP, perhaps that's a good thing though. An epic looking car all the same with options to make it stand out out blend in with the sticker pack.
If you won't compromise on specification or doors for that matter the TCR is the best choice. A lot of them are kitted out, especially the later ones that had Akrapovic exhausts and rear cameras as standard, as well as there's a good few in 3 door in a selection of colours. (That Parkway Leciester one seems to be the best in spec and value at the minute, but has been up for sale since what seems like March so might get a little off. I wouldn't be put off if it was an ex-VW press car at least it'll have been properly bedded in.)
The Edition 40 is a bit of a hard sell, given how their prices are currently so similar to that of the TCR's or 7.5 GTI PP's which have less miles. They're a fantastic looking car in white or red, but the aesthetic is lost when in dark grey or black as they hide the nice gloss black bits. As well as it's hard to find a 3 door one with any kind of specification, as well as the Alcantara steering wheel will most likely need reupholstered as this point on any with a bit more miles.
Currently 3 door Ed40's range from £23,000 with 36,000 miles to £30,000 with 13,000 miles, with some spec on each. Whilst the 7.5 GTI PP's are around the £20,000-£26,000 range but little to no specification at this point, private sales would be a good shout here if you can get one young enough where it still has main warranty but they did have more standard versus the Ed40 (Heated seats on all, rear camera on 2019 models).
Personally I would only buy from Main Dealer in the current sales climate, as their prices stayed reasonable with the chip shortage whilst other places inflated prices, as well as you get 2 years warranty.
Good luck with the hunt.