Adding Options/Variants to our Shopify Store

We need someone who has good experience with adding options and variants to a Shopify store. We are launching a Shopify jewelry store in the next two weeks which has about a thousand items in it. The store is almost complete and all stock has been uploaded. Now we have to add 1 or 2 option/variants to each piece, each with it's own SKU, and price variants. Options include gold-type (White/Rose/Yellow, and combinations of these colours), ring size (about 10 options), chain options (about 6 options, each with an additional price). About 25% of the pieces only have gold-type options - no second option or price variants . The website is divided into different collections, so we will do each collection seperately - generally 50 to 150 items at a time, until it is all done. I have some completed examples on the website, and their corresponding csv file. Fortunately, a lot of the work will be copy/paste although SKUs & prices will need doing individually. It must be completed in a week or less, and the freelancer who gets the project must have a good amount of experience doing this before.