I am going to be doing some HOT weather hog hunting.

Any recommendations for hydration pack type, size, and ease of use?

I've been looking at the Eberlstock Mini-Me pack.  I haven't stocked them up to this point, but a friend had one that really impressed me.  Hydration capabilities, plus room for a lot more.  It also has a built in mesh bag that allows you to carry extra clothing as the day warms up.  Very nice little compact pack with lots of capacity.

Here is a link to the Mini Me pack.  I'm going to order some to have in stock for the shows this summer.
http://eberlestock.com/H1%20Mini-Me.htm

I would recomend buying a platypus hoser.  This is a basic hydration bladder only.  They come in 1 Liter, 1.8 L, 2 L, and 3 Liter.  They cost between 20 and 24 dollars and are extremely tough.  They can be inserted into any pack you like.

I have one that has lasted 5 years of constant carry in the harshest of conditions you could imagine.  

You might also consider buys a bite valve and drink tube insulator.  

I am a firm believer of these types of hydration systems.  It makes drinking easily accessible and relatively quiet.  you can carry any pack you like and are not tied down to a particular brand.  Platypus bladders are exceptionally tough and cost efficient.  

Good luck and let us know how it all works out.

Thanks guys.  I will look into both.

I like the camelbak Mule

I have a CamelBak also, think it's the Mule. It has two storage pockets. Well made, and just the right size for a day out in the woods.

Ken,
Sent you an e-mail.