There is nothing wrong with what you are proposing but like you said get advice from your solicitor/conveyancer as well as your accountant.
The bank will need to take into account all your ongoing debts for all applicants, this includes mortgages, credit cards, personal/car loans renting appliances/furniture etc. Existing debts can have a much bigger impact on borrowing capacity then people think. best way will be to go to whoever you want to get your loan through & get them to run through all the scenarios including what your possible borrowing power can be down the track assuming you buy this property then want to buy another one down the track. Even if you have enough equity, your borrowing capacity will determine if the bank can provide the total loan amount you are after.
Be aware that if all 4 of you are chipping in to buy a home all 4 of you will be on the property title & loan. If something was to happen that would mean taking someone off the title for any reason the Land titles office will charge equivalent stamp duty for that persons share being taken off. In your case if all 4 of you are buying the property by default you will each be allocated an equal share (25%) of the title unless you agree to a different share before settlement. This has a flow-on effect to how much each of you can potentially claim on negative gearing. So eg. If one person wants out on the property for whatever reason their 25% stamp duty that was paid at the time now has to be paid by the remaining 3 title owners. There can be exemptions in the case of owner occupied properties but you need to put some research into this for your situation.
There are a few other things that can eat away at the profitability of what you are proposing but by all means don't let it scare you off, just be aware of the big picture...
Most banks will charge Lenders Mortgage Insurance if you have less than a 20% deposit upfront. The total premium you will be charged is based on the total % of the loan versus the value of the property.
If you rent out the property you need to have landlords insurance, there are council bills/(+ strata if a unit or townhouse) water/ electricity. Property managers will take their % of the rent if you go that way.
Hope that helps. Good luck with whatever you are trying to do