How to vendor finance?

I believe to have found a property that is undervalued.

It's a 2 bedders, found within 10k from Melbourne CBD.
The problem that I'm facing right now is I don't really know how to vendor finance it.

This is what I have been thinking of doing, but the numbers won't work.

– Offer what the seller wants if he lets me pay the amount in installments, i.e 100k each year.
– Get a loan of 100k P&I each year from the bank?
– In the mean time, I would have placed ads to secure some tenants to rent the property for $1200 a month, providing some cashflow, making it a +vely geared property for the first year

And this is where I get stucked… I don't think the bank will lend me 100k each year. Also, after the first year, I will have a loan of a bit less than 200k. With the current interest rates at 10%, the interest repayment will be $2000 each month. This will then make the property -vely geared.

Can anyone out there give me some ideas?

Thank you.