I have both They are each wonderful in their own very different ways. For where you are right now in your life, an '05 or newer S-type would be a much better fit. If you must have a 4.0 XK8, find one that's already had all the weak areas addressed, otherwise repair costs are prohibitive.

Re the Miata, I've had 4 of them all the earlier NAs ('90-97). Great minimalist sports cars & very reliable, but in no way near a Jag in refinement, room, performance or liveability.

 

Wow! You really are having a hard time with making logical decisions exclusive of motoring passion! Vintage Stingrays happen to be my hobby, and its JUST a hobby. Given my experience, I wouldn't have recommended one as a daily driver even when they were new. They're beautiful and fun to drive, but fragile and complicated. I haven't seen anything on any Jaguar that holds a candle to the complexity of the Stingray's vacuum-controlled everything systems. Its evil genius kind of stuff. WHEN it goes wrong, it makes you really mad and you need to find a scientist to diagnose it. And the rear-end design which integrates the half-shafts as a primary link of the suspension is incredibly hard on the rear wheel bearings. I suggest you look up the cost of shipping the trailing arms off to be rebuilt as its not a DIY job. And unless you have a garage to park it in at the college dorm, the T-tops notoriously leak and of course will pour water in once they're stolen. The air conditioning is pathetic. There's three fan speeds, 1) "Is it on?", 2) "I think I hear the fan motor running." and 3) "Ahh, I think I feel it a little bit now." By contrast the heat is outstanding in winter, even when the heater doesn't work. They're really only pleasant to drive with the tops off and rear window removed (68-72only) on a 70-80 degree day - i.e. best enjoyed just a hobby. I could go on but you get the idea.