Mate depending on the length of your hunt just get a comfortable pack that can fit the amount of gear in it that you need.
I have a badlands hypervent that has 2 pockets that clip around with the waist strap but more and more I'm finding that i use it less and opt for the camel back style for quite short hunts or the big 70ltr mountain pack for the week long jobs.
I reckon you probably need 3 packs: 1 for avo hunts, 1 for day hunts and one that can fit all your sleeping and cooking kit for a few nights. Some might find a pack that would be good for 2 of those situations but not all 3.
At the end of this month I'm getting choppered in to the west coast of NZ. I'll be taking a mountain pack in with a smaller camelbak style rolled up for day walks while I cache the big fella at camp.
You'll also find when your hunting the same places after a while you don't have as much need for a GPS or other crap that you used to deem essential so you don't really need the pockets on the front. Now I tend to lean more towards just a small bottle of talc in the pocket, a leather cartridge holder and knife on the belt, a set of bino's with elastic harness to keep it close to the chest, and a back pack with a waterbottle, jumper/raincoat, radio, headlamp, spare batts and map and compass if I really get bumf'd.
I'd advise against getting a chest rig you don't really need that many pockets, they are constrictive, make you sweat more and if anyone sees you You u might look a bit ridiculous.
Also if your a bit short on cash like you said ex military surplice stiff is cheap, just find good ways of waterproofing everything.
But if you need to check the map all the time, big map pockets are the way to go!
Good luck