Unicorn Windows - .27 U-factor French Casement for OITC

The .27 can be worked around if needed, but ideally they meet it. I have 48x48 rough openings that cannot easily/cheaply be modified and the options are gliders that barely meet egress or french casements that are an actual upgrade. The number one issue is sound abatement with a focus on bass (wonderful neighbors, just pretend it's an airport issue) and i'm looking at a laminated dissimilar with the exterior pane laminated.

To simplify everything it's gotta be a .27 U-factor and it turns out that this is a unicorn to find for some reason. I'm looking at Marvin Ultimates, as the cost to modify negates the premium. Open to other options as well. Curious if a dissimilar tripane will accomplish the same OITC. Surely I'm not the first person to have this issue or go down this path. I figure if I'm going to replace windows I might as well do it well instead of cheaply with regret. Reddit, do your thing.