I think with your future goal in mind which is to eventually have a bigger website with everything from every website, it is better to go with Option 1. Having an umbrella brand and then having sub-brands within it will make it easier for the customers to relate to the brand once you implement your final goal of the bigger Amazon-like website.

This also doesn't hurt your need to make customers feel that they are a part of something that identifies with them. You could have your Action Sports website for example to talk directly to the right Action Sports customers. You just need to have some kind of branding indicating that this site is a part of umbrella brand. I can't see how this can hurt. In fact, this could even be done without completely different websites for every category. You could have one site with different category landing pages that lead to listing pages that only contain stuff from that category like Action Sports for example. Shopify has done a lot of these kinds of landing pages that are very effective. Have a look at these two which are aimed towards ebook authors and pet suppliers respectively:
http://www.shopify.com/sell/ebooks
http://www.shopify.com/sell/pet-supplies

But I think you've already got the separates website working? It's fine and could work well. What you're trying to do is really good. I have a lot more suggestions in mind which could make your sites a lot more effective and make more conversions/revenue eventually. I would be happy to discuss this in detail through a call.