Justin,
We are in the same boat as you, more or less.  We want to use a cycle
retention that the courier can support and reclaim the tapes coming backup.
I posted an example of how to do this about a week ago, but probably did not
garner much respect because it seems like a really dumb thing to do.
However, it really simplified our rotation and eliminated reclamation
management.

To do what I do, you may need the DRM product set (DRMEDIA Table).
Essentially, what I do is select all tapes that are going to come back in 2
weeks and move their data to new tapes in the copy pool.  This causes TSM to
take the data from the onsite PRIMARY pool and build tapes to go offsite
this week for the stuff that is going to come back next week.  That causes
the offsite tapes to be placed in a VAULTRETRIEVE status.  The command that
I issue to find out what is coming back is:

select * from drmedia where upd_date < current_timestamp - 14 days

That tells me what is coming back soon.  You can get elaborate and select
only the volume name and pipe the stuff into the commands necessary to issue
the commands dynamically, but I just do them manually right now.  We are
heading down the automated path soon.

The command that I use to move the data is:

move data [volume_name] stg=[same_copy_pool]

By doing this I am not exposed and I my operations department was able to
continue a tape rotation they are used do.  The side effect is reclamation
is automatically done by doing this.  I love 2 bird solutions.

You can accomplish this without the DRM module, but I like the MOVE DRMEDIA
functionality becuase it automates a lot of stuff for me.