While looking through my recent Cabela's fly fishing catalog I saw that NFO (Noth Fork Outdoors) had some interesting hybrid mini rafts. Some were a combination of belly-boat float tube and a pontoon raft that is nearly framless other than a foot rest. Some of these boats were fairly light weight, none of them cheap. Considering the Alaska pack raft community I would think that this style of boat would find a niche up here outside of fly fishing.
NFO Outlaw Renegade is one of the boats shown in the fly fishing catalog. No weight listed on the page, but the catalog said 28 pounds and 800 pound capacity.
Alaska fishing video