I would imagine you'd need to syn them, as meat is only free when all visible fat is removed-and pancetta is quite fatty if I'm thinking of the correct thing
Just used the search facility on here, and found several threads about pancetta, and one states it's 3.5 syns for 28g. HTH
Depending on how many portions you are making i'd make the recipe with the pancetta and syn it. I find that using a substitute just isn't as satisfying- especially with stuff like pancetta and chorizo. The meal will well be worth the 3 syns!!