I'd use EBC clutch plates off ebay, I think Honda CR250 clutch plates are the same as I had some laying around the garage that I used that had 'KA5' stamped on them, which is a Honda CR250 (early 80's I think) code.
I wanted heavy-duty clutch springs because the stock slips like a bastard, I ordered some EBC CSK007 springs that are listed as HD springs for the 250A5 but I found the larger diameter wire (smaller ID) would bind on the posts making the pull very heavy, I ended up using stock KDX400 clutch springs with are stronger without the binding issues.
I am looking at trying to fit a KDX400 complete clutch (5 plates versus 4), I think I may have to use a KDX mainshaft, it'll take me a while to confirm all the engagement concerns with all the gears though.
