I ordered an HBR07 from Light Carbon when I bought my frame from them. I was only about $100 extra, and the quality was excellent. I only had two notes:
* The included computer mount didn't support Wahoo bike computers, even though they claimed (at the time) that it did. I did eventually find one on AliExpress that fits.
* The holes for internal cable routing are rather small, so I don't advice you try to fit both a hydraulic hose and an outer cable in there. This is clearly aimed at electronic groupsets.
They don't have a MOQ, but it may be the case that they don't sell these handlebars separately, as the shipping may cost more than the handlebars themselves. In my case, they just added the handlebars to my frame box.