Re: Product Custom Options - is this the best method??
Custom options are easier than Configurable products, but with them you will not be able to track stock of your variations.
If you need some method to massively add them to products, default Magento does not allow to import them or copy and paste from one product to another. It is possible to achieve using extension (there are multiple).
One of them Store Manager for Magento. You can do it with 2-week free version that you can download from the link in my signature. It allows to copy-paste custom options and export/import them.