Hi,
you could create a
document type that will represent suppliers. Then you could create documents in the content tree and assign
categories to documents. Using a repeater web part you can filter documents according to your needs.
To allow members rate and comment suppliers you could use a
message board web part. You can insert one web part to some parent document and the web part will be visible on all child, but comments will be unique for each page. They are connected with document (page). Rating is a part of this web part.
As for your third requirement - could you please provide more details, maybe some example?
Thank you
Best regards,
Ivana Tomanikova