Here are some pics from CAD.
Front:
(openings for 120 fans, stock fan guards will mount here; rack mounting holes, holes for handles if desired, mounting for RJ45 pass through connectors, some holes far cable management (zip ties for now:))

looks nice, two suggestions:
1) KISS. Make the front and rear identical, similar to this image. might not rack as nicely without bottom/top/sides, but allows clean 3-wide builds
2) Re-design it so that 3*120mm fans cool 8-10 blades packed more densely. This would be terrific for those underclocking to 150GH/210W.