Of the two options you presented I would go with the Corbin. I have that seat on my 79 KZ 1000 LTD. The LTD tank is so much smaller than the standard you have so the proportions are better. I always ride mine with a tank bag so that helps. Really liking the fairing, I have the same but full size and do not like it....after seeing yours I am going to modify mine. Back to the seats: I did a longish stretch with a stock LTD seat and was only able to put 210 miles before I had to give up....The Corbin let me crank out 400+ miles and that is enough for me to decide which one to use. BTW, I absolutely love the classic S.E.V. Marshall stickers....brought me back to my youth.
You might consider a seat off a police model. I have an 81 rebuild project that I put a stock police seat on and was amazed at the level of comfort it had. I have a 2012 Victory tour that the seat is not as comfortable as that old police seat.
Cant take credit for it. I did the fiberglass base and poured/carved the foam but the upholstery was from my better half. The first attempt looked fantastic but was a bit loose.This was her 2nd attempt.