As far as categories go, under Toys & Hobbies>Models & Kits, there is a Figures category. It contains auctions for figures of all kinds, and that's where I see a lot of finished connoisseur figures. So that's one place you could post your auctions. Don't be put off by resin anime figures in the category.
There's no right or wrong, though. That is, you won't get in trouble if you put a bust under Housewares. It just might not be as visible to category searches. But you won't get dinged by eBay for it. It's more important to use titles that will cover more keywords, for keyword searches.
Hope that helps, prosit!
Brad