Unsupported means that you don't have a chance to get new supplies liked food.
Lightweight shelters fall into several categories:
Hammocks-great personal shelter for one. Hennesy Hammocks are a well know brand name but you can make your own fairly cheaply. Search for the look at
www.hammockforums.net for more information
Tarps-everything from a cheap piece of plastic hung between two trees to shaped, silnylon specialty tarps. Very light weight but you have to know what you are doing to stay dry and staying bug free can be a problem.
Tarptents- Sixmoondesigns, Tarptents, and Gossamergear all sell good quality, single wall, tarp tents. Light in weight, bug proof protection. Tarp tents can have condensation problems or 'misting' in heavy rain-a condition where a fine mist of water comes down on you while you are in the tent.
Double wall tents-Big Agnes Seedhouse design and the Mountain Saftey Research Hubba Hubba get good reviews. Heavier than tarp tents, these tents have a mesh inner tent that is covered by a rain fly. Good bug and rain protection. Hilleberg, a European tent maker, also gets rave reviews. Their tents tend to be heavier, more storm worth and expensive.
Personally, I use a Sierra Designs Clipflashlight. It is small, relatively light, relatively cheap, has good rain and bug protection but can have condensation problems. I will eventually upgrade to a tarp tent but don't have the money to spend on one right now.
If you are going alone and have trees available, I'd at least look at something like a jungle hammock. I'd also look at any of the two person, 3 season tents from tent makers like Sierra Designs, Kelty, and Eureka, and the tarp tents from the companies mentioned above. Look for enough room to be comfortable away from the bugs, good air flow to prevent the insides from feeling like a sauna, and a price you can afford. Anything in these categories will make a good shelter to start with and let you decide what you really want later on. Hope this helps.