Hi bigblock,
Good luck with the internal frame backpack! Getting it adjusted to fit you properly will be the first order of business as if this is not done its likely it will not be as comfortable to use as it could be. Try looking on line for setup instructions from the manufacturer.
I like external backpack frames as I can strip the pack from the frame and then use the frame, shoulder pads and waist belt as a "freighter" frame. In this configuration "stuff" can be tied to the frame, I usually put "stuff" in some sort of burlap sack or cloth bag or duffel bag just to help from loosing things while hiking. This same idea can be applied to internal packs by tying "stuff" to the lashing straps on the outside of the pack. I should caution you that this method will allow a person to fill the insides of the pack and then strap more on the outside of the pack and in the end the entire thing is too heavy to pick up much less carry.
Try to protect the inside as well as the outside of the pack from sharp edges: shovels, sluice boxes, picks, etc I put small sharp things in old socks or apply a tough tape to the sharp edge or point. My pack has been in use now for some 15 years and is still in good shape and I've carried some horrible loads with stuff inside and strapped to the outside. It is important to take care of the pack as it allows you to carry your gear in as well as out of where you want to go. If the pack fails because the side of it rips open then your life getting all your stuff back out is not going to be fun.
Go for it! 63bkpkr