Well the fact that you’re only allowed to go +2 isn’t really an issue since, for a T32, there aren’t really any good (load-rated) options in 20” tyres anyway. Without going (IMHO) excessively big like 275/40/R20.
So 18” or 19” is good! Depends perhaps on usage & style:
In 19” there is a really good sweet spot for a wider sporty tyre at 255/45/R19 (basically like the standard 18” Sportline but without looking as undersized as they do!).
Or in 18” if you prefer a less wide and low-profile sporty look (although note the above is not stupidly low profile by any means) which can work well with more swamper tyre look but also looks good generally then look at 235/55/R18.
There’s also the OEM Sportline standard 255/45/R18 but I and many others think it looks a little under-tyred - ie just a wee bit too small - since it’s actually smaller than the standard eg 215/60/R17s. Good for acceleration I suppose (given gearing).
There are a few other funky options including ‘staggered‘.
(I have a large spreadsheet of tyre options, load ratings, and availability of summer, all-season and winter tyre availability/price across 17-20” wheels! )