I think (but am not an expert) that the fastest route for you but also most expensive and awkward would be the scsi kit onto the blizzard than a mk6 sdtoscsi adapter.
After that probably a fast ata adapter (never used one)
After that probably something like an idefix express but be aware that with my b1260 I never got above.2.5 or so because I think there is an issue where the b1260 is a limiting factor.
I probably have a thread here or on amibay where I asked similar questions a few years ago which documents my adventure down this road.
EDIT - some info here:
http://eab.abime.net/showpost.php?p=785335&postcount=15