Thank you very much!
(http://www.berrienbuggy.com/08966e60.jpg)
(http://img.photobucket.com/albums/v81/bigbuba/watercar2wc3.jpg)
Yea... after looking around a bit, I see a lot of VW beetles turned into dune buggies but that's not exactly suitable. The kind you showed looks good, just like Stan's, and with the open back you can do all the modifications and set-up nice and easy, and then it's open for people to see.
So buying one would be nice, building one might be easier in the long run, then you have everything just they way you need it, and it's a clean start. It might be hard to find one like that for sale too... and then shipping it to where I live (Canada) from somewhere in the states is going to cost ~$2000, so you have to add that to the price no matter what the vehicle is.
Now for building one, the only thing is that there is a Kit Car of a Cobra 427 sitting in my garage right now waiting to be built, so it takes approximately the same effort to build that as it will a dune buggy, except that is going to be over 500 hp with a big-block V8, where as the dune buggy would be about 50 hp which makes it easier to run on water... at least until everything is figured out and you can get the cell size down and the efficiency up to feed a huge engine like that.
I am definitely a head of myself, but It's nice to line up my dreams, so I'm ready for them!