Not a bar light, but look into ViparSpectra XS4000. It’s perfect for your space. And the test results on https://www.cocoforcannabis.com/ speak for themselves.
I have only run a 2x4 once and used a Mars Hydro SP3000. It’s long and narrow. In effect a bar light. But one bar. I can tell you this. I would not hesitate to get this style of light over a flat panel style for sure.
That ultra is too much for a 2x4, and that is an led for a 4x4 area, the have cheaper smaller options, plus almost everyone is using same diodes and drivers, just go with one with good quality parts and build, you will getfor what you pay for, if wanna go sure with your investment the go with lab tested equipment you know what you getting, Cheers and Happy Growing