theres Acurate Armour they make a very good Challenger 2 but you pay the price
they also make everything else you would need to put on the Trumpiter kit
http://www.accurate-armour.com/
decals here http://www.xs4all.nl/~cromwell/
Eduard make PE sets for it http://www.eduard.com/
have a look on this site for some there some by other companys ive seen on here http://pmms.webace.com.au/newkitnews/newf.htm
and heres a review of the Trupiters Challenger 2 http://www.jbwholesalers.com.au/reviews/trumpeter/tr00308.htm