8th of August update, you can now get 5% for just a 4 year term:
Bank of Queensland BOQ 4 year fixed rate term deposit top interest rate.
Or still go with the 5 year for 5%. Who knows what interest rates will do in the next 4 to 5 years. At present almost all of them seem to be dropping by about .1% every month. Start of the year it wasn't unheard of to get get 5.75% instant access!