I haven't camped out of an Outback. However, I have done many multi-day whitewater kayak trips, including a lot in the 1-2 week range. There is a lot more room in an Outback than in all but the biggest whitewater kayaks, so you could do extended trips in an Outback. I have the following suggestions:
1. Pack like a backpacker, not like a rafter. You should be able to carry about twice as much gear in an Outback as most backpackers carry, but nevertheless, pack lightly. Don't feel obligated to use all the space which is available in the kayak.
2. You can strap a big dry bag onto the back of your Outback, and drop several dry bags into the front hatch. The big trick will be to figure out how to utilize the space under the rear hatch and the hatch between your legs. These round hatches are small in diameter, and whatever dry bags you put in them need to be small enough to stuff through the hatches, and flexible enough to bend as you slide the bags back inside the kayak. You'll need to figure out which gear can be fit inside the round hatches, and which gear is too big or inflexible to go inside the round hatches. You'll need to invest in some small-diameter flexible nylon dry bags to slide through the round hatches. Don't rely on plastic bags such as ziplock freezer bags to keep your gear dry, because it only takes a grain of sand inside your kayak, or a hard projection inside a bag, to abrade a hole in a plastic bag. A plastic bag covered with a nylon stuff sack is semi-safe. Try to lay heavy gear on the bottom of your kayak rather than storing it in the dry bag behind your seat, to keep your center of gravity low.
3. Gear which you'll need while you are on the water should be packed where it's readily accessible on the water, such as in a small dry bag right behind your seat, or in the round hatch between your legs. Gear which you may want during the day while you're on shore, such as a pair of hiking boots, can be stored in a somewhat less accessible location. Emergency gear and gear which you only need when you stop to camp can packed at the bottom of your dry bag or be slid back into the cavities of your kayak.
4. If you will be wearing a dry suit, you can wear the same clothing on and off the water. If your clothing is likely to get wet while you are out on the water, or there is a chance that you could end up in the water, you'll need to bring a complete change of clothing for use on the shore. But don't bring four changes of clothing. Remember, pack like a backpacker.
5. Do some two-day overnight fishing trips to fine tune your gear. Prepare a gear list, which will make it much easier to pack for trips, and will make it less likely that you will forget something important. Every time you realize you need something, add it to the list. Every time you realize you haven't been using something, take it off the list.
6. It's easy to be comfortable while camping in warm dry weather. It takes a bit more gear and experience to be comfortable in lousy weather. Intentionally go camping in lousy weather, so you will figure out what it takes to be comfortable in lousy weather. For example, I always bring a 10' x 12' waterproof tarp, which is big enough for three or four people to hang out and cook under in the rain. Rig it low for better rain protection, and sit under it in "Crazy Creek" style camp chairs.
7. Once you can comfortably do overnight trips in a variety of weather, the only difference between a two-day trip and a two-week trip is the amount of food you bring, plus possibly some more repair and emergency equipment.
Get out there and have some fun.