I've pm'd you but for the benefit of others, these kind of sub-niches are almost impossible to get..
It's just not necessary. The broad niche is what you go after for a domain. If you want to put up a site about drones, then a tech domain is fine, you don't need a drone domain for example.
A shapewear site will work on anything shopping/ecommerce/fashion related.
Broad domains, folks. Health, entertainment, shopping, business, finance, tech etc. There aren't that many domains out there, so if you want something that's A) In a rare niche, B) strong, C) clean and D) cheap, it's just not going to happen. It could take me 6 months to find a suitable, brandable, clean shapewear domain.