I found this company last week who look like they make nice Bolt kits:
Unfortunately the resellers listed in there "Where to Buy" list don't seem to sell the products so I've sent them an email asking where I can buy them from. However if they don't respond they list each bolt required for the 350Z DE, HR and even Nismo and have good PDF fitting guides:
DE: http://www.galleryfr...03-06-Guide.pdf
HR: http://www.galleryfr...07-08-Guide.pdf
Nismo: http://www.galleryfr...Nismo-Guide.pdf
You can cross reference the codes in the PDFs on the following page which give each bolts specs:
http://www.galleryfresh.com/2.html
For example, 8S and 8SW (Washer) are these:
I'll update this post if I get a response or if I find a supplier who can do similar bolts using the above info. Maybe others would like to order if I'm getting them from the US to reduce postage.
Haydn.