I love the idea of a Cyberpunk Berserk AU in general.
Guts is his bad BFS-wielding self, though I wouldn't put heavy weapons like an LMG or minigun past the guy either, since the guy is superhumanly strong. Casca in the meantime could be a swordinator as well, though I also wouldn't put being a razorgirl or a gunslinger past her either in this particular verse.
Judging by Guts's white patch and his new hand and cybereye, some form of Griffith incident may have gone down in their past, though one that went down entirely differently than in Berserk canon. Neither Guts nor Casca have the infamous Brands of Sacrifice on them, and Casca's in better shape than she was post-Eclipse. I have this image in my head of Griffith being some kind of corpo, or perhaps someone who's become a Rogue AI if we want to go the Femto route with him, but he's definitely someone these two are gonna have to contend with at some point.

Zodd: "Hey buddy, I think you got the wrong door. The leather club's two blocks down."