Acoustic pickup for classical guitar for use with Rocksmith

Ok, bit of a long story, but the gist is my Romanian metalhead friend wants to get two friends of hers back in Romania Rocksmith for Christmas, since they've Lready mastered Guitar Hero and she'd kind of like them to actually learn something useful from it. Problem is, they only own a classical guitar, and she does 't have room to fly back with an electric.

So, are there pickups out there that could work with a nylon string acoustic? She's not so worried about sound quality - "after all, their favorite band is Slayer" - as long as it picks up the signal and sends it to something that can plug into a 1/4" jack.

Thanks!