I did this swap in the fall... and have put about 35k on it so far. I think I have finally dialed the front in, and am going to share the details on this thread to keep the info in the same spot as opposed to making a new one.
For reference, I have an 04 3500 with the 6.0 that had 260k on it when I did the swap.
Springs and lift:
I bought new OEM top side spring/shock buckets as well as new springs from my local Ford dealer but I have connections there... oemfordpart.com is probably cheaper than walking into most dealers, about half what retail would have been at my Dealer. That site also allows you to see the different spring rate options for the super duty.
I used coil spring Part # 5c3z-5310-ga which is the lightest spring rating available. Compared to the springs from my diesel donor truck they are about half the coils and a lot thinner. I can't imagine using those... it would surely ride crazy rough. I feel like if I were to do it again I would use the same springs, I don't feel they are too soft by any means. If there was a softer one I might consider that even... but I am overall very happy with these springs. Rides like a truck but not abusively so.
I mounted the spring buckets flush to the bottom of the frame rail, which I think Johny did too, but I have seen others lower them so that is why I mention it. With this spring and that mount height I think I gained about 8.5" lift up front, after adding a winch behind the bumper and plenty of settling out those new springs. That seems like a lot but I think that is about perfect for this swap, and keep in mind I had 260k on it so I was probably sagging a bit, and my 8.5 might be different than a lower mile van. It is about 28.5" from center of hub to bottom of fender, and was about 20" to start.
I mounted the factory ford sway bar to the chevy frame and it works fine, however I have had one link removed almost the entire time. I just don't feel like it needs it honestly, which I was very surprised to have be the case. It really just doesn't body roll or sway much at all even without it.