I'd buy some 8k boxes - they're designed for shipping and I would guess would work our cheaper / lighter than custom.

M Customer since 1991...
2 Channel: 818v3 into 8000SE's running Roon on a Nucleus One with QNAP TVS-871-i7-16G 8 Bay NAS
Cinema: 861v8, 2 x M6's, 7200HCSE + DSW
Office: Explorer 2 into Shure SE846's
Kitchen: AD88
Other Stuff: Philips 77" 4k OLED Ambilight TV. Hue Lighting System, ATV 4K & a lot of Apple stuff...