Nice Pano Para
Ok so to see I made a test file same size as your original 9764 x 2585
uploaded to bags of love and then played with the size to see the examples
So 48"x12" will give you a small crop at the ends or 60x12 a little top and bottom.
The best way to make sure you get exactly what you order, is to ooutput your file from Ps at the right size
Very simple to use auto crop tool in PS see pic 3
EG say you go for 60"x12" and use bagsoflove you require 200DPI
set your crop tool to the 60in x 12in (plus wrap) 200DPI and draw your crop where you want it
To work out the wrap just add it to the size so 60x12 or in new money 150x30 with a 2.5cm wrap (1")
Set Photoshop crop tool to 158cm x 36cm 200dpi
Save at max JPG and upload job done
see detailed info on canvas with wrap here
Artworking Instructions for Canvas Prints
Of course I do not work and have no conection with Contrado, only that I use them and they are the best IMHO
Doug