Firstly, No. You can't
The SD ones are made by SuperSprox.
They have only been bought by 1 dealer in UK currently who's up in Fife. (according to Supersprox, no-one else has bought them)
They only come in 42 rear. Which i purchased and will run with a 17 front.
Which will give pretty much the same gearing as a 16/39 (close enough to the 16 40 you want.)
they're £50 and will require a chain with 3 links more.
I'll find the name of the dealer in a minute using search.