Okay, I will elaborate...
As I see it, sourcing commercial single wheels for a Fuso in the US or Canada is challenging, to say the least.
In the multitude of posts on this forum that discuss the acquisition of singles in the Northern Hemisphere there is information on local businesses that are willing/able to make single wheels.
The GUTS is not an Australian model either, so it is highly unlikely that a specific GUTS single wheel would be available here.
The PCD for a 6 stud FG Canter is 222.25mm (8.75").
If the PCD on the GUTS is the same as this then any of the singles for the FG will fit, but the offset may not be exactly right, so you may not get an equal track on the front and rear, which is one of the main reasons for changing to singles. Remember... with singles you flip the wheels front and back, so the offset is very important.
I think that it would be very unlikely that you would find an "off the shelf" set of singles specifically for a Fuso GUTS.
If you do want singles, all you should need is the PCD of the studs and to calculate the required offset in order to have a suitable set manufactured.