I agree, Bernie Makhraz at Norwest is a top bloke, don't bother at Parra Lifestyle, they are tools...I can recommend Greg Liebeck at Fairfield Car Radio also, they have been around for over 20 years and are the best IMHO. If you ask Bill nicely he will give you a demo in his daily driver Astra, the cleanest sounding vehicle I have ever heard.
FRISKI on these forums runs AKIRA Sound on the Hume Hwy Lansvale, I'm sure he will give you a great deal.
Remember you get what you pay for, most places can afford to go to 5-8% on top of cost price, however they do a shit install and you can't trust them...after-sales service is very, very important to me.