Wow, I actually worked on a disk like that awhile ago, never quite finished it but it was/is just lacking some final touches.
I use AmiTCP which I stripped all unnecessary stuff out of, then I used smbfs for mounting a Samba share to boot from. When booting just let the Startup-Sequence reassign all necessary stuff such as SYS: Libs: S: Devs: and so on to the Network share and then execute it's Startup-Sequence. Uhm. Well. Good Luck!
