http://www.optactical.com/tagreboar.html
That is the TAG version of a maritime CIRAS, might suit you.
Eek, used to be 405$. Now 475$
About the Eagle PC, I think it is put on in a similar way to a CIRAS but is not releasable so I doubt you woul be able to use a CIRAS sling with it but something like this should work.
http://www.blueforcegear.com/product.cfm?t...id=5&prod_id=73