Having packed moose, caribou, blacktail deer, and sheep in Alaska since the mid-70's with everything from cheesy Kelty frame packs to every brand of internal frame packs I have a couple of well-earned opinions.
First, if you want a do-it-all pack, get a quality internal frame pack with removable frame. The two best are Kifaru and Mystery Ranch.
Second, an internal frame pack with large sack can be made small (for day trips) using compression straps or can be big (for large-volume packing) by expanding the compression straps. You can also remove the sack and just use the frame for carrying odd loads with just the frame.
Third, external frame packs by definition do not conform to the shape of your body. As a result they can and often do load the heaviest portion of your pack burden farthest away from your iliac crest. Definitely bad juju.
Anyone can carry anything once or twice with any sort of pack. If you might use it once or twice it really doesn't matter what you get. But if you want what can and will last you for a couple of decades of hard use then get the highest-quality internal frame pack (with a large compressible/expandable bag) you can buy and be done with it.