This version of RasPI has no ethernet connectivity; just an USB data port and GPIO.
Could you not use a USB ethernet adapter or wifi? I missed the part if you truly can have no Ethernet that would be a big issue if so.
In terms of changing the controller-scape, Avalon can only be mentioned as a detail to Bitmaintech, for all the good things Avalon that may be. I can not see the appeal of a Pi ZERO over Bitmaintech's chosen BB derivative, not even price (and not to mention connectivity, or the lack of it - USB to ethernet considered).
How many Bitmain miners have you had? Wait till one day you have trouble with one or brick it.... sadly it can happen. With RPI you can go to local store and buy one quick and if you have backup flash it and be up in no time. But with custom bitmain controllers you have to wait for it to be shipped to you through RMA process, unless they are nice and let you buy it without sending back.
RPI has lots of advantages.