By default you will receive z4 atx 200 with 5-7.4 converter that fits with dell 240w/330w or voodoo 350w.
For proximity, i mean you need to bend wire that output from bulging power button, do not let the button push on dc-dc block.
Otherwise with config, you can go for rx460 or any gpu without any pci express connector, with no big issue.
What i don't know if you will have coil whine on load, I didn't try with gpu. With my core i7 6700k on occt test, there was a very very tiny coil whine (only hearable at 20 cm).
Ps : cool that you are considering id cooling is-vc45+noctua fan, a true beast..