The LSD kit is the only way to go imho. It took me two days to fit the kit but I would recommend getting a professional bodyshop to install them as some bits can be a little fiddly. Imho again, they really do suit the 350, especially with the frameless doors and are stable in wind as well if tack welded on. As for Jays ones, he had a different design of hinge system to the LSD ones and he did suffer from droopage (enter comments here) but on the new LSD kits, I have not experienced anything like that and once setup for height etc have been perfect with no shift. The other advantage to the LSD kits is that you can still open the door 3/4 of the way like a standard door and then raise them meaning you don't have to always use them to get in/out of the car.
I am a dealer for the LSD doors so if you are interested, drop me a PM and I will sort you out a price for them.