http://www.aussiedisposals.com.au/hi-co ... k?___SID=UI have one of these, very good but learnt soon enough that after you load it up with water and a little bit of gear you can barely fit a backstrap in there! Well made and quiet.
I would reccomed popping into an aussie disposals, they have a good range. I ended up buying one of these as well.
http://www.aussiedisposals.com.au/hi-co ... 0?___SID=UMuch bigger than what you need but it has a 5l bum-bag that clips onto the outside which can be used as a standalone pack.
I have found that I can load all my survival and meat processing gear into the bumbag which I then jam into the main compartment with my meat bags, this keep the outside of the pack streamlined from snags.
Then during carryout I have loaded up the main compartment with meat, clipped the bumbag back on the outside and the bag has a handy harness system for the rifle which leaves hands free for a leg/trophy.