Rack Pulls will work if for no other reason that to Deadlift big you need to Deadlift often. However the Deadlift typically takes longer to recover from, so variation is perfect there.
I had a lot of luck with a routine made up by a fella called Olly Jackson, which included cycling doubles for the deadlift and assistance as deadlifts from two different heights.
I put it into an excel spreadsheet years ago and it's been on my computer since, i've uploaded it if anyone's interested:
Olly.xls