You didn't mention how large the tear in the surround was, because if the problem is a simple tear and not the result of "foam rot," it is often pretty easy to repair.
The "new" foam surrounds are quite an improvement over the older formulations that would fall apart after a decade or so. I should point out that the "rubber" surrounds also have problems, with work hardening and splitting over time, not to mention that the foam has a certain amount of edge damping that terminates standing waves on the cone itself.
I would recommend replacing foam surrounds with the "new" foam surrounds.
Best Regards,
TerryO