Need help with setting up store. Use attributes, or add more products.

I am setting up a store selling fishing weights. I set up a product called "Fishing Weights" but now, after reading, I think I've run into a problem.

The fishing weights come in different sizes and weights. I was going to use 2 attributes, one to select size, then one to select weight but I think I would need to use "Product Attribute Grid" to get the 2 drop down menus I would need, since there are only certain sizes available for certain weights. And to make it worse, depending on what combination of size, weights and quantity they pick will adjust price and shipping weight as well.

So is my other only real option is to add individually as a separate product each, a fishing weight that is "x" big, and is "y" oz?

I don't know how many sizes and weights you have, but you may have to create a separate product for each weight, then use attributes for the sizes, or vice-versa, depending on whether there are fewer weights or sizes.