guess its all about cost vs results. You already have a remap/CAI/cat back exhaust so you're probably running at 270 bhp ish? Unless I have missed a few mods here. From my understanding the cats will prob push that up by 10 bhp.
Cats are cheaper than a supercharger but wont give you anywhere near as much power. What kind of power output are you after Jackie? 350-400 bhp??
I think you can get upto about 300 bhp without a charger by adding manifolds and cams to the above list. THat would be pretty much fast enough for me if I had the money!! That may be a safer 300bhp too, unlikely those parts will fail, that is versus a supercharger which probably has a higher rate of problems than the afformentioned upgrades.
Guess its really down to how much power you want. If you are after 350+bhp then go for the supercharger. think cats are important too tho at some stage in your upgrades.