Looks great, for the SBC, a nvidia jetson based might also be a great option, something like jetson nano/NX as they have the same power delivery.
If you are looking for an -almost- as powerful SBC (with m.2 support as I see you have it in the original design), give a look at Rock5-B (1), I didn’t test it personally unlike nVidia ones, but it seems it has a great specs, as you might also struggle to secure jetson ones sometimes due to stocks being sold out.
(1) https://ameridroid.com/collections/rock5-model-b/products/ro...
Hapy Hacking!