Aside from price, it's a tough call between the two. Like the Loadmaster-style frame that Dana developed, the Kelty 50th Anniversary ($240; www.kelty.com) uses non-metal "springs" (in this case, carbon fiber) to match some of the flex that is so appealing in an internal-frame pack. I don't doubt that the Kelty engineers looked very carefully at the Dana packs and used them as a reference point.
The trouble with the Dana packs currently available is that it's hard to find the Loadmaster Longbed, the most successful design in my opinion. Their Terraframe is essentially a Terraplane internal-frame pack bag grafted on to an external frame, and the wedding is not 100 percent happy. To my mind, a really well-designed external-frame pack bag is easier to pack than an internal-frame one. So while I like my Terraframeit carries big loads like a dreamI wish it had the Longbed bag.
Still, all that said, a decision on what to do is pretty easy, really. If you can find a Terraframe for $99 that fits, buy it.