It's probably not necessary to create a special ad pack as such, because ClassiPress already includes a manual payment option as well as PayPal, which allows you to moderate ads until the payment has been manually made/confirmed in the way you describe. Rather than automatically deleting after 3 days, the ad would not be published until you have manually approved it based on payment.
Outside of the PayPal and bank transfer payment methods, we do also have a
Google Checkout plugin available for ClassiPress at this time. There are some planned changes for the payment setup in our themes such as ClassiPress which will give more options for payment gateways in future as well. Thanks.