Newbie Owner With Wheel/tyre Dilemma

[Chadders]

Hi all
I have a T6 T30 lowered by 30 mm currently running on 20 inch rims with 255/35 r20 tyres ....... what combination of tyres and rims would give me a less harsh ride
Thinking of 18 inch rims with 255/45/18 Goodyear tyres not at all keen on low profiles
Seems a bit of a minefield guidance much appreciated

 

[Wills]

You should be running a 40 aspect ratio tyre with the 255. 275 for a 35.
Factory 18’s use a 255 / 45 as standard.