Go with the bank u have all your history with.
I have been with commonwealth since i was 5 (now 27). I applied for an unsecured personal load the other car to buy a VZ/VE SS Ute.
Got approved for 36k on the spot. The lady said I had a great Banking history with the bank and she also tried to up my credit card limit another 8K at the same time(I declined I don't need the temptation). Start by getting a small credit card and build history with your bank. Buy the car with your saved cash and the credit card. Never miss a payment and anyways pay as much as you can every months. Makes you look good.