2000 and up Jags didn't have the Nikasil sleeves. The upper timing chain guides seem to wear and need to be done I think every 80k miles. The Jag V8 is a good engine but not as good as MB's V8. Jag has never had the r&d money that MB has. I think the timing chain design on the new V8's is a little weak.
What about a 97 XJR? Can't go wrong with the I6.
What about an S600? In my area clean 95's are in the very low $20k range. Want to dance with the devil?

That V12 sure sings an awsome song.