I have both the esci and the italeri and they are not the same. In fact the italeri cockpit looked like it was an older version of the esci.
regarding the rest of the 1/12 frame you can buy a frame that is typically used for R/C which will save you a lot of trouble scratch building - (if you don't mind moving to fibre glass instead of resin and plastic :)
PS I did buy the resin 1/12 aftermarket F-16 pilot off eBay he looks pretty good and when he's done someday he'll look alot like me (lol)
(worth mentioning that all three are still unopened on the top shelf of a cupboard waiting for time to stand still :)