I'm not aware of anyone supplying specific 'kits' do do this but your best bet would be a donor cab,it should be cheaper that way too.
There are vendors of brand new complete cabs out there (Premier) but i'm not whether you could buy the individual panels from them if you'd prefer new....

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.