I'd still say they are polished fronts, and will still have the same issues in the winter, the wheel choice is however yours though.
As for the numbers:
5x120 is the wheel stud pattern and that's the correct T6 one.
40mm is the offset and determines where the wheel sits under the arch in laymens terms. Further in, further out (poke) etc.
ET40 on an 8" wheel will fit and not rub, even with a 30mm spring.
As for load rating, that's not quoted. LK are sods for not putting the load rating on their website, but should know if you call them. Don't always take the word from a seller that they are the correct load rating, because often they have no idea and just say it's fine. Best to ask what they are rated up to.
There are loads of threads on wheels, including the detailed one that
@Fish has quoted above. One thing I will say, it's an absolute mine field looking for the right wheel, and it has most members spending hours researching a wheel that suits a T32. Many give up and put of factory fit alloys, or even better, things like the 18" Amarok steels that sound like they wouldn't work visually, but actually give one of the best looks on a lowered T6 in my opinion. (plus the bonus they are rated high enough and are only a few hundred pounds for a new set)
Good luck and don't forget to actually sleep when you're on the hunt for the perfect wheel.
