I would say stay away from non-OEM inks. I went through this with my Epson 4800 and it was a nightmare! Clogged heads, lines and inconsistent output were just a few of my problems. Ended up spending nearly a week cleaning the 4800 because of a cheap ink trial. Real funny because I have Mimaki large format solvent ink printer and never-ever spent more than a day repairing that $30k monster.
I do have a Pro 9000 as well, so I'm not comparing apples and oranges. Oh, and my inks looked EXACTLY like the inks in the link you posted.
My recommendation is to definitely stay away from the non OEM inks. Not only will they cause problems with your printers internals, but the quality always seems to be lacking as well, AND the long life of the prints coming out of the Pro 9000 will be no more after the switch. I'm sure you will find a few non-OEM inks that produce acceptable results out of the box, but they are few and far between & none will measure up to the mountains of money Canon spent on R & D for their Chromalife series Inks.
Just my 2¢...hope it helps some.