Emax

I need some advice.  I am buying a esi-4000 rack from a friend with 
Turbo.  He suggests I get an external HD that is compatable and cable 
to connect to the exi-4000.  He is not impressed with the zip drive.  
What HD can I get ,what size memory, and what external cable end 
connectors do I need?  He has the complete 12 sample disc cataloge from 
emu that he will download into the external HD once I get it.  Will 
this HD and cable also work on the SCSI of my emax HDSE?  Another 
question, can I transfer samples from my emax to the esi via SCSI cable 
directly, or do I have to go to the HD first?  Or what is your take on 
all this?  Thanks for all your advice and help.  -Alan