Still looking, Dennis the Scopestuff people must have known the postage would have been out of this world so didn't bother replying to my email
Thanks to those who have replied, all very helpful.
The sort of thing I am looking for would be maybe 500 x 200 with ribbing for stiffness on the bottom along with a "D" size dovetail to connect to the mount then lots of holes to allow for a variety of mounting options. The only thing I have seen locally is one that MyAstro shop has.