I tried the aluminum ferrules but I could not crimp them at all. I couldn't find any tubing that wasn't huge so I got some copper plates and folded them over the wires several times then crimped the bejesus out of them. It seems to be holding well enough and I can shift properly but it does look really stupid. It only needs to hold up a couple weeks at most and if it does break then it should not cause any problems because the stays will keep the cable from going anywhere important, I just won't be able to shift for the rest of my ride. Now I just have to find some decent handgrips that don't cost 30 bucks and figure out what shifter to order.