600 Karma, race costs 2x its BP cost. Max attributes 5 + racial modifiers; max skill is 1 at 5 or 2 at 4. Remember that you won't be able to get much in the way of 'ware maintenance (much less replacement), and that the FAB will eat magic users without some sort of protection. Assume the character grew up there, so no ex-military with milspec bioware getting stranded.

I built a guy with a crossbow (so I wouldn't have to worry about ammo; easy enough to make your own bolts) with melee hardening and Clubs (Parry +2), with some cyberware and no bio. How would you go about it?

Harley Davidson Scorpion with a suncell and a ram plate. Or,

Unarmed adept with Sustenence, and maybe Celerity. Or,

Magician with Sterilize who doesn't worry much about summoning spirits. Or,

Infected, as long as you choose something that isn't Dual-Natured. There are people to eat, yes?

What's a CCZ?

I think it stands for Chicago Containment Zone. i.e. Bug City after the nuke and the FAB bombardment. Supplies and access to stuff like reliable electricity, uncontaminated food and water, ammunition, medical care are all scarce.

FAB makes active foci, spirits and astrally perceiving mages QUITE unhappy, but a mage who doesn't astrally perceive can be everyone's best friend with liberal use of Nutrition and Sterilize.