Hi
I recommend you to buy OS 3.1 ROMs and AmigaOS 3.9 for your A3000.
The benefits are really great and if you want to "network" and go into internet, you will need AmigaOS 3.1 anyway (I think), because you will not get any working browser or email-client for AmigaOS 2.1.
If you order AmigaOS 3.9 you will get Genesis-TCP/IP and the AWeb-Browser this way, they are on the CD (of cause AWeb is now GPL and free downloadable from internet).
If you bought your A3000 by eBay, why don't you try to buy a SCSI-CDRom there ? They are really cheap (32X Plextor SCSI-II has cost me 7,- EUR incl. shipping). If you look there you may also find 3.1 ROMs (rare, you need special ROMs for an A3000, couldn't use any other) and AmigaOS 3.9 (once a week).
Noster