How to handle this purchase Invoice!?

Hi there,

Please can anyone tell me how to handle this purchase invoice, i try Tax-es but does not work for me.

In my country you can buy items with 0%, 8% or 18% VAT rates.

but if the supplier is not TAXABLE then all of these products you will buy with 0% VAT.

In case when the supplier is TAXABLE then you will buy products with 0%, 8% or 18% VAT.

p.s.
    Item                VAT        Price after VAT
    Apple         18% vat        1.18
    Milk                   8% vat        1.08
    Cow water bowl   0% vat        9.00

Look the purchase invoice
[img]http://www.pictureshack.us/thumbs/13753_supplier_invoice.png[/img]

I have create three taxes 0%, 8% and 18%.
I create three items with 0%, 8% and 18%.
I create a supplier, what tax should I choose to work properly like  the screenshot?