The JaguarSport wheels by Momo are pretty nice. When I bought my XJR-S I found that someone had swapped the original wheel for a standard airbag item, Yuk. After a few years scouring eBay I happened upon an original XJR-S steering wheel, NOS, original packaging. The seller didn’t really know what they had, so I got it pretty cheap.
But it was just the bare wheel, no mounting boss. For some reason it was damn difficult to find a Momo->Jaguar boss, so I took to eBay again. Cheapest way to get one was to buy a S/H complete wheel and boss from an early XJ40 based XJR.
Turns out I really didn’t care for the ten past ten style that the (correct) XJR-S wheel enforced, and I much prefered the quarter past nine of feel of the old XJ40 item I got from eBay. So that’s what I installed on the car.
Both are 14.5" - not sure how much smaller that is than a stock wheel, but they are a lot thicker, with a much better feel.
[ Just had add an edit - sorry, I rotated that picture to show the wheel attached to the car the right way up, but it looks a bit odd. ]