Many of our shops have more than a thousand products. All our plans have unlimited products and each product can have a finite number of product variants (I think it is 50). Its the product variant that has a SKU assigned to it. In short I think the answer to your question is yes.
Also this question doesn't really belong in the API forum, I would suggest posting in the Shopify Discussion forum or contacting Shopify support for questions on using Shopify.
Cheers!
Kevin