Welcome to SaleHoo!
I was so excited to read your post; you're doing precisely what we recommend our members to do by selling a few things around the home, and building up to developing a product line!
Thinking about incorporating your hobbies into your eBay business is also a great idea.
In terms of a few products to research that are related to you interests, I've read good things about these:
Life jackets and vests, archery bows and arrows, rock climbing helmets and shoes, vintage fishing lures, and roof racks.
Photography is also a good niche to get into, but there is a lot of competition, so there are a few items that you should steer clear of due to over saturation of the market, such as:
Photo tents and cubes, telescopes and binoculars. You will also find that most consumer grade cameras are difficult to sell as many sellers are already doing this, and will be hard to compete with.