Dunning Letters

Hi Experts,

we have configured dunning letters in R12.1.3, the below is our requirement, any one suggest me we how can  i achieve the below requirement.

#Requriement

For dunning letter, we would like to setup with attachment of invoice.Is it possible?

For delivery of dunning letter, the prefer method would be: If dunning contact email is available, then email, if not, then print.

We would like to have dunning plan setup based on invoice transaction types rather than customer profile class?

Send only consolidate dunning letter per customer per bucket (i.e. same customer may receive 2 or 3 dunning letters depends on how many buckets it hits at that month) with list of invoice and amount due per invoice.