CFA wont be using Digital radios for some time. they have digital compatable radios, but there is no plan to roll out a Digital network to support it in the next few years.... well.. there is a plan, but lets say there is no infrasturcutre built, so the next few years an analogue scanner will serve you well (and be dirt cheap!!). Unless you want to listen to MFB or Metro Ambulance, forking out the $500 ish for a digital scanner is perhaps redundant.
The Apps for iPhone/Droid will give you scanner feeds, sometimes "live" sometimes on upto 3-4 minute delay. depends on how "live" you want your live to be.
Rural VicPol and Rural Ambulance are also on VHF high band (on a type of SMR, but with fixed channels on most bases) along with VicSES. Anyone who is decoding the encrytped Metro VicPol (and is streaming that on the 'net) is obviously cruising for chat with Mr Plod. Metro Ambo and MFB is unencrypted APCO 25 digital, VicPolice is encrypted. I happen to know someone who has had some high priced laywers look at the legislation and decrypting the Police's encrytped digital radio is likely to contravene a number of laws including the anti-terrorism laws (which seeing as you can be held indefinatley under those, are not something you want to fall foul of!!!) So beware anyone who tries to flog you a set that they say you can listen to metro cops on because you cant! Rural cops yes, metro. No.
I'd consider a cheap analogue scanner because CFA wont be fully digital for a few years yet.