Take data from cubecart and create google base feed file, either manual or auto upload via cron job.
Specific product attributes will need to be added to the website pages ie MPN, ISBN ETC ETC but these can be purchased and installed or built yourself.
One other column for the feed will tell google which adds relate to which product.
Much more info is available and currently our old site on cc4 is doing this except the extra column.
I personally would have no problem for the site to be scraped, my web host may get a bit upset!