I've suggested this to landlords before and it worked. If this one won't accept it, then as others have suggested either borrow the money or walk away.
Hope you find a solution.
You could ask the landlord if they will accept Swiss Caution for the first year and then you cancel it and place the deposit in a rental surety account. You would have to make this a condition in the lease agreement.
Isn't that exactly what reserves are for?
Hehehe yes, exactly what my husband said when I was in full panic mode...his words and a nice glass of wine helped.