Some ifs:
You wish to maintain FireWire connection and to be able to boot from external storage—yes, I know that this is the 68K MLA—make sure that the bridge to internal devices is mediated by an Oxford chip and not a Prolific (which is by far the commonest in gear coming out of Asia).
You wish to be ambitious or innovative or have plain fast transfers, there is up-and-coming eSATA, which relies on not using USB or FireWire interconnection.
de
You wish to maintain FireWire connection and to be able to boot from external storage—yes, I know that this is the 68K MLA—make sure that the bridge to internal devices is mediated by an Oxford chip and not a Prolific (which is by far the commonest in gear coming out of Asia).
You wish to be ambitious or innovative or have plain fast transfers, there is up-and-coming eSATA, which relies on not using USB or FireWire interconnection.
de