How to avoid transaction ID wrap

OK, here's my problem, I have a nature study where we have about 10 video
cameras taking 15 frames per second.
For each frame we make a few transactions on a PostgreSQL database.
We want to keep about a years worth of data at any specific time.
We have triggers that fire is something interesting is found on insert.
We want this thing to run for a log time.
>From the numbers, you can see the PostgreSQL database is VERY loaded.
Running VACUUM may not always be possible without losing data.
The numbers I have amount to 466,560,000 transactions per month, lasting a
maximum of about 9 months until XID wrap.

I am thinking about a few work arounds, BEGIN/COMMIT to reduce the number
of transactions, COPY, etc. so I'm not dead in the water, but I would be
interested in any observations yo may have.