As a former bike messenger, I’ve ridden a ton of different fixed gear and track bikes in all possible weather conditions. The bikes we use take a massive beating, so you quickly figure out what works and what doesn’t.
Firstly, don’t go with the cheapest option. Even really expensive, high quality fixed gear bikes are cheap compared to road bikes and still last much longer and require virtually no care. It pays off big time to invest a bit more in a quality frame and components.
In my experience, Fixie Inc bikes are absolute garbage. I wouldn’t use one as a door stop. I’ve never ridden Mango bikes, but based on the website specs they don’t look too promising. Same goes for the Orro FE.
Really, the best thing to do is buy components and frame separately. Either put them together yourself or let a bike shop do it. For frames, I would look into Engine 11, Cinelli, Specialized, Dolan, or Look. Miche make really good cranksets and durable wheels, but DT Swiss also have some good quality options. There is a humungous second hand market for track frames and components, and by mixing used and new gear, you could easily build an excellent quality bike for 1,000-2,000 usd. Trust me, you’ll be happy you spent a bit more. You’re gonna be using the bike all the time, in all weather conditions, so it pays off. If you really want to buy a complete build, 8bar, Surly, and Cinelli make some decent ones.