Jimbo: I know the ones, I had a good look at both while I was in Japan.
I have only seen the squarer versions on sale here.
I just checked the Greddy offerings and I stand corrected, the round shape tanks have a 9 or 15mm option, the squarer tanks have a 6 or 10mm option.
Bare in mind the hose that comes with the kit in garbage and probably wont be enough for you anyway, as tosh said, UAS has some spring reinforced hose that perfect for such an application, or you could go the braided option which is considerably dearer.