I think I would suggest a canoe if you and your wife are going. A good two man canoe is as light or lighter than two ul boats. Even a UL 16' boat will weigh about 35-40lbs. I am assuming a week or there abouts for duration(?), though with heavier loads it could still be done fairly easily.
I have done many trips of that length and much longer around the ADK's. Going from Old Forge across the Northern Forest Caone Trail to Plattsburg with a meander through Fish Creek Ponds/St Regis in about 3 weeks solo (carrying the canoe and gear on all portages.) About 10 days from Inlet up the Oswathachie to Low's Lake (Bog River) and back. Another across the Saranac Lakes to Fish Creek ponds and back in 5 days. Another across Indian Lake, to West Canada lakes via Moose River Plains. Well, I really like my small 12'6" stripper. At 21 pounds, it is realtivly easy to portage but real good on the water. Across Lake Champlain it was a surprisingly stable little boat. It has well over 1700 miles on it. A days paddle means about 40mi once you get in shape for paddling. 20mi is a practice run, getting in shape on flat water.
I pack fairly light. Pack weight was ~40 pounds at the heaviest for three weeks unsupported. I lost about 10 pounds of body fat…I could afford it, easily, ha ha.
No cooler, I picked up a couple beers at some gas stations here and there when the going was easy. I used a two man tarp and screen tent, due to the bugs. And the old SVEA for wet weather. Wood fire for good weather when there was a fire pit. My daughter and I did the Oswagathcie trip with ~23lb each for ten days and a 18' kevlar boat we portaged 7mi into Low's Lake. We also brought the stevensons 2rw, an 11×9 tarp, the SVEA, and 2-12oz fuel bottles included in that weight. Neither of us lost more than 2lbs on that trip. We ran out of food *just* at the last lunch before the car. Feul was down to about 2oz. Nearly a perfectly planned trip.
When I was younger, my brother and I carried 24-28 pounds of small pack rafts into some "fishing holes" I won't mention. They are still good fishing holes. After a few uses they ALWAYS needed repairs and patches. 'Corse, neither of us had the money to buy good ones. At the end of three seasons, they were dead. Soo, I am partial to canoes. The ones I make are just as light, and hold up to class I and class II rapids fine, dispite being UL cedar. I documented my techniques at cedarstripcanoes@yahoogroups.com. At least two or three years old, now. The canoe got a re-skin after the NFCT and works fine, even today. Damm good boats.
Mostly, they let you carry a weeks food with UL gear AND the boat, spraydeck, lifevest, and paddle for around a week at 45-48lb. Light enough to carry for 12 miles and still be able to paddle for another 15mi, set up camp, cut firewood, make supper and have a beer watching the sunset.