Yes it's possible, you'll need a lot of hairspray IMO, but it's not impossible to get something like the second picture
For dreads, because I had some synthetic dreads in the past, putting them on a wig isn't my cup of tea BUT you have some tutorials for that, You'll need to make a loop at the end of the dread and attaching it to the hairs and braid the hairs to the dread
here's a tutorial to make dreads if you don't have some...
http://www.youtube.com/watch?v=ihlxsA-R0ZE
hope it helped, if you have others questions, feel free to ask me !