most farm and ranch supply stores carry rope and various hardware, hooks etc. i don't know how mechanically skilled you are but you could make a shoulder harness out of it. i would suggest you put the weight a little lower though, around the waist preferably. reason, it's easier to pull with the waist than with the shoulder. lower center of gravity. i would think a visit to any good sporting goods store would have deer drags. cabelas and bass pro shops usually have all the goodies you need.
also a good section of rope is good to throw over a branch to hang the deer and gut it. makes the job a lot easier. and cleaner. when you start to drag the deer don't do like mr. dumbie, "me" , did and drag it backward. it's amazing how resistant that fur is going the wrong way.
drag 'em head first.
look around, i'm sure you will find all the equipment you need plus some. don't forget a good gut hook knife also.
before i forget, welcome to the forum.
have a good hunt.
may st. hubertus smile on you.