In case anyone is thinking of taking the plunge, I just ordered two cab front covers from gig.ink.
All I can say at the moment is the ordering process has been simple, reasonably hi res pictures and accurate measurements, and you're good to go.
Had help with the artwork from the guy who designed the band artwork to make sure it all ties in nicely, otherwise it seems idiot proof.
Next stage is they email a mock up for me to check before they print it.
Watch this space.