Long Term Retention

Two part question:

1. I have many customers that require their data must be maintained for 7-10 years. Using a Data Retention Plan of say 1 full/wk with 6 incremental. How would I go about automating a plan for saving or copying a backup so I could have long term availability to retain 1 backup/Mth or 1 backup/Qtr or even just 1 annual to meet these requirements?

2. Is there a way that these long term backups can be deduplicated as a chain to reduce the amount of storage that they will accumulate?