Performance Intake recomendations?

I don't have an answer for you but you could try to find a Jaguar enthusiast website, the members know what's available and may have reported successes or problems that you would find useful in your search. Or contact a Jaguar specialist and ask what he's found to be useful. If you want to find a Jag specialist, here's our directory link for you: https://repairpal.com/jaguar-repair-in-valrico-florida