I see two different Bilstein Shocks for front of 2002 XJ8. They are 24-023733 and 24-023757. Which are replacements for original?

 

Since yours is not supercharged I would asume the standard softer ( comfort ) shock . Also look at the upper and lower attachment bushings .

 

Check this thread, should help...https://www.jaguarforums.com/forum/xj-xj8-xjr-x308-27/got-x308-blues-x-3-a-182903/
The big issue for any automotive parts is when they upgrade. Did they change the number or is that number a different model, as your asking. I'd do some Bing/Google searches to see what returns.