I can't comment on the Ford, because I haven't driven it, but here's my verdict:
- Ferrari (jtv setup): quick, especially on acceleration. Tires wore out faster in the rear, so it was increasingly difficult to hold it on the track. 7 laps are possible, but 6&7 are not pretty.
- Jag (Praiano setup): You think you are mighty quick, because you can push it a lot harder than the Ferrari, but it's slower on acceleration and top speed, so overall times are not as quick after all. Higher speeds in corners, and very forgiving. I managed to do 8 laps pretty well, but also had to take it slow on the last one. Might even be capable of doing 9.
Summary: It's a 33 lap distance, so that means 8 lap stints will not give you any advantage, unless you can also do 9 at least once. So that means you either do a) 6*3+5*3, b) 7*3+6*2 or c) 9*1+8*3.
I would say Ford and Ferrari will be either on a) or b), while Jag will either be on b) or c).
The Jag might be slightly slower on sheer speed, but you might make up more than that by making less mistakes over the duration of the race (and maybe one less pitstop). It's also more than possible to follow in the slipstream of a Ford or Ferrari.
So, since I won't be able to race, I can give away what my choice would be: the Jag and strategy b).