Awesome work so far! I'm very curious to see the suspension setup.
I've contemplated adapting L322 suspension to my E53... it would be a lot of work and basically everything would need to be swapped (oil pan, diff, axles, control arms, knuckles, outer tie rods, etc.) and would need to make an adapter plate for the top of the strut.
I wonder if it would be possible to weld new brackets on the E53 subframe to accept the L322 control arms?