That kit would probably work OK. Personally I'd cut the expanded part of the tube off, use a chop saw to make straight cuts and weld them up. IF your really good you could also figure out what pieces you need i.e. how many 90's 45's and straights and buy them locally at an industrial or fleet supply store, maybe even an exhaust shop?
When you weld them, tack them in place and then turn your welder way down and weld fast. Exhaust pipe is thin and you can easily blow all sorts of holes in it, plus it welds kind of messy because of the aluminum coating. I used a high temp exhaust paint to go over the welded junctions.
