It looks like you're new here. If you want to get involved, click one of these buttons!
Why folding? Is it for lack of storage space? Or because you also want to travel with it?
If lack of space, you may want to read the article on kayaking and small living spaces in Issue #9 - Summer 2012 issue of California Kayaker Magazine. It can be read online for free at http://www.calpaddlermag.com/magazine.html. It gives the pros and cons of a variety of options.
If for travel, then you also want one that meets your travel needs. Folding boats come in all sorts of shapes, so make sure the one you get meets your needs.
I have a Trak, which I found to be the closest to a lower volume touring kayak in feel. Feathercraft seem to be higher volume, so great for long trips (though they do have multiple models, so they may also have a low volume one or other styles). PakBoat also has many models, so make sure you look for one that meets your paddling goals if you go that direction.
three travel kayaks, showing a size comparison
A Valley Nordkapp 3 piece glass
A Feathercraft Khatsalano folder
A TRAK T 1600 folder
Need to paste entire link