Land Tax and equity release for IP?

Hi People, my first post here, building a house at the moment and it should be complete in 3 months time. Always interested in investing money in the IP rather than money in shares, got burnt once and never again in shares. Havent had the chance to speak to a bank yet but wants to get some ideas first from the more knowelegable IP investors before going to the banks.

My numbers:

My income: $48000 gross, full time job (retail industry, sorry it is the lowest paid industry)
My wife: $17000 gross, part time job (she is doing part time job in the retail industry as well, crap! But she also just started studying as well)

Our estimated value of our house once completed: $600000 (this figure is from an very educated guess through a real estate agent)
Loan still owes the bank: $230000
Savings in the offset account: $50000

As you can see we are not wealthy people at all, we worked very hard when we are in our 20's, but we want to get into the IP market while we are still young, my wife and I are both 33 this year.

With our annual incomes and above, what are the chances the banks will lend us say $350000 for a 3 x 1 villa or unit? Since we have $50000 in savings, we are happy to use that as well.

And since our PPOR land is worth about $340000 on the market, and say the estimated villa block is 280sqm in size, do we have to pay any land tax on the IP?

Thanks heaps guys.