There is a source for the better Epson dyes in Epson printers;
http://forum.luminous-landscape.com/index.php?topic=82703.0
I would not recommend it for the HP model though, thermal heads may not cope with inks for piëzo heads. The quoted Epson B6070 is a CMYK model so not optimal for photography, variable droplet sizes but no minimum droplet size indicated. The HP Vivera dye inks have a good reputation too but ...
As noted at the end of the previous thread, I used and still use the Noritsu-sourced "Claria" dyes in Epson printers. The last wide format printer I used them in was an old Epson 4000. See
http://www.paulroark.com/BW-Info/4000-Noritsu-2K.pdf, which is a full color system. I reverse engineered the dilution base, so dilute colors and K are easy to mix. Today, however, the dyes are in my every-day Epson WorkForce 1100 only, and I doubt I'll ever sell prints made with these dyes in galleries again. They may win the beauty contest, but they also are not, in my view, lightfast enough to be sold as "fine art."
Last year I took apart a print that had been framed for the 2013 show. It already showed a visible difference between the areas under the frame and the areas that were exposed to light. The print was on Red River metallic paper, sprayed with Lascaux, and displayed without glazing.
Unlike our pigment inksets where the carbon based black inks are tougher than the color pigments, with the Claria/Noritsu dyes the black is the weakest, and I think that weakness is not being measured in the Wilhelm tests. In the Aardenburg-Imaging testing, the 100% K does OK, but look at the next darkest patch, which is where the highest concentration of the black ink would be. It shows more fade.
I'm a B&W printer, so using as much of the black dye as possible was to avoid the metamerism of the color dyes, but it was a double edged sword.
As to the HP dyes, I tested those in one of my Epson printers and found that they were not compatible with the Epson and third party carbon inks I also use. They also had metamerism that was much worse than the Claria dyes.
So, I'm a fan of the Claria/Noritsu dyes for non-fine art purposes, but while they are a huge step up over the older Epson dyes, they are not in the pigment class when it comes to longevity.
Paul
www.PaulRoark.com