One of my favourite places to buy corsetry is a Gothic clothing site called HeavyRed.com. They’re well made, beautiful, suitable for waist-training and tightlacing, and (best of all!) well priced.
They carry two main styles with variations upon them-
These are my favourite from Heavy Red. I actually own the above corset but in a deep blue. Have been wearing it and abusing it for years. They have also been coming out with many new underbust designs that work well with steampunk and other everyday outfits as well as many new fabric options.
I own one Heavy Red overbust and holy sparkling goats it is beautiful! My only complaint is that they are not as well designed for curves as the waist cinchers. There’s not a whole lot of bust room built in (although this may be improving based on the photos I’ve seen) and the waist does not come in as dramatically as it would in a waist cincher— an adaptation often necessitated by society today and its lack of regular corset wearing!
Overall I highly recommend HeavyRed, they’re wonderful to buy from and very well priced in their corsetry section.