Paul Roark has done some b&w ink blends with the HP PK. He has some tone curves and comments in other threads on tonality, papers, and other ink blends. I don't know if he compares tge Canon inks at all:
http://www.paulroark.com/BW-Info/HP-C6.pdfI don't know the Canon inks, software, or machine. If you look at what Paul has done over the years, you will see results from one K to many K inks on different machines. What is good enough varies with drop size, dither patterns, etc.
I am going to mix up a custom b&w ink set from the HP Vivera Photo Black this summer, for glossy only printing with GLOP on a 7600. I will also buy a 1400 for the same ink set.
With the 7600, I will blend K, LK, LLK, etc. just to fill the 6 slots, plus the GLOP is 7. Or, I will add a to ing color ink, depending on native hue on the papers I use. I did that in the past with the Eboni that Paul likes, but wants a glossy only ink set. I mixed one last year with Epsons PK, but didn't like the slightly greenish blacks I got. Nice glossy ink set though overall. Most ink sets are optimized for matte papers, or try to do both.
Depends on whether you can dedicate a printer and create your own profiles. It is not a bad proposition though if you get a used wide format for a reasonable price. For about $140 for 400ml of HP PK, you can make 6 200ml dilutions (plus maybe $10 for the 1 liter of glycerin/ water mix.)
Michael