Nice one! I like what you are planning, when these buggies were new they were competitive against cars like the XX4 - which as we know ended up being re-released after team drivers started using them instead of the newer XXX4.... using this logic your racer Cat2000 EC should prove to still be relatively 'handy' against the more modern buggies.
With regard to the shell I understand this might be the correct shell for the lay-down shock cars?? - but it would be worth checking the part# in the manual or a phone call to the factory before clicking the buy-it button!
http://www.racing-cars.com/sp/catego...nd_Decals.html
P.S; i've got those purple bulkhead pieces on an old SST, including the lower front one piece part.... however I have seen pictures that shown different one peice parts for the other areas that match the design more of the plastic parts.... maybe i'm getting confused with the CAT 3000?