The early A3000s used a "SuperKickstart". It was dubbed something like a 1.4 ROM. I have one around here, somewhere. It could boot the machine far enough to mount the internal hd and load a kickstart image from that. I have heard that this was done because the A3000 went to production before 2.0 ROMs were finished. (Hence the final 2.0 is 2.04) Also, you could copy additional ROM images to your HD, and boot the A3000 with both mouse-buttons down, and use the "SuperKickstart" early startup to select which ROM image you wanted to be loaded that startup. (I'm not sure any ROM images other than a 1.3, and the 2.04 were ever released for the SuperKickstart, though)
The A1000 was always sold a "kickstart" floppy disk-based machine, though there was an expansion available (fit in a chip-socket?) to put a 1.3 ROM chip in it. I believe that accepted a standard A500/2000 ROM.
As for a 3.0 ROM chip... I'm not sure those are good for much, other than as a spare for someone who still runs 3.0. ;-) I had previously thought the Amiga ROM chips mostly indestructible, but several people have posted about destroying them, lately......... You never know...