My favorite dog pack is the RuffWear Palisades. It has a separate harness, making it easy to remove the pack bags at rest stops and allowing the use of just the harness in difficult places. It is a remarkably stable pack, too.
Both the RuffWear pack and the Kelty pack I used previously do put most of the weight on the front shoulders. Of course the fit depends on the individual dog, just as backpack fit depends on the individual human. I suspect that what you're hearing about Wolf packs may be advertising hype.
In my avatar Hysson is wearing his old Kelty pack. Here's a picture of him in the Wind Rivers last summer modeling his RuffWear Palisades pack (older model):
If you're referring to the For Sale (buy/sell) section, forum policies (which I hope you've read) state that you need 3 months' membership or 10 approved posts or to make a donation before you can post to that section. I believe that this rule is to keep people from joining only to post items for sale. I suspect also that there is a desire to know people better before doing business with them. In the meantime, welcome to the forum!