$10 Walmart bicycle cables in a 4 pack could do in a pinch, and at that price, you could afford wire cutters. Get knarps at an auto parts store if you need them.
Again, I say "in a pinch" as the wire parts are about half the diameter of what I saw at Detroit Moped Works last week. I wouldn't trust them on a kitted bike with a 300 pound rider going 50 mph.
The front brake cable has always been too short for a standard moped handlebar, but might work on a cafe racer.
Make sure you cut the correct end off of the shifter cables when using them for brake cables. There's a small cylindrical end and a barrel end, cut the cylindrical end off as it slips through the brake cable thingies in the hand levers. (edited)