Cafe Racer seat for my kz 750

I recently got this bike from my buddy, with the plan to make it into a cafe racer style bike. For about four months now Ive been trying to find a seat that I liked for it but A. no one builds them for my bike and B. I don't like the look of the ones Ive found that people said i could make fit . So I'm gonna try to make one myself. I'm sure this is going to be harder than i think but i figure hey i got you guys to help. Here is what i got so far. I have already built the fiberglass seat pan. It's not perfect, far from it, but its my first time using fiberglass to make anything so I'm pretty proud of myself for how it came out. So now I'm on to the foam and I was hoping you all had some ideas for what kind of foam i should use for the basic shape in the back. I'm trying to upload pics but they are all to large so bear with me.

I made one a few years back and documented the process I went through. I used foam to make the shape like you are planning to do. You can see how I went about it here: Fibreglass Cafe Seat Build

Thanks for the info here is the seat pan i built. I'm planning on using just foam to make the cafe racer seat shape and then covering the whole thing with vinyl or leather.

I probably should have smoothed out the frame more so i would have had an easier time laying the fiberglass but it fits like a glove so I'm happy with it. I was also able to use the stock rear bracket to mount it.

Oh, sorry. When you said foam, my mind automatically thought of the foam I used, wasn't thinking straight

Pan looks good. Will look nice once you get the foam on and shaped, and it all covered.