Drive one with both the 20" and the 19" tires. At least in the USA, and I think it is the same in the UK, the 20" tires are summer performance tires. Even though you may not get a lot of snow in most of the UK, it does get cold, plus the car does ride a little stiffer with the 20" tires. The 19" are all-season.
The adaptive cruise control is nice. The version with leather interior is only available in one color...if you like it, fine. I have what's called the Loft interior in the USA, and find it comfortable. Too early to tell how well it will wear.
Personally, I don't like sunroofs, partly for the headroom, partly for the potential leaks and noises, and partly for the cost. Some find it an essential option. Given I use mine for mostly short-distance running around, long distance travel isn't an issue, and I did not find them a big deal, nor did I find the REx option useful. Your results may differ considerably. England has lots more effort into CCS charging stations than most of the USA (none close enough to me to ever use), so you may find the CCS charging critical.