He looks like an AQHA show horse, not something I would breed any mare of mine to. I pretty much only deal with AQHA horses and that is all I have right now for my own horses but you want to look for ones out of working cow horse lines that aren't Hancock. The Hancock horses are where a lot of the color in AQHA horses are coming from in Montana, Wyoming, Idaho etc. right now and they tend to be high hocked and straight hocked.
I looked at that horses pedigree and he has nothing in it for working ranch horse lines that I would personally ever consider for my own horses.
You want good bone and good legs and a horse that can work all day. In order to get that you usually need to look at working cow horse competition horses, cutting horses, and especially ranch horses. Just make sure if you look at cutting horse studs that they aren't throwing down hill offspring. Stay away from the Western pleasure etc. lines if you want a horse that can do serious all day work.
If you can find them see if you can find something from a Skipper W line. They were bred to be all around working horses and some of those Skipper W lines have color as well. I have one Skipper W horse that is red roan and he has feet like sledge hammers, tons of leg bone and I have worked cattle on him for an entire day and at the end of the day he still has gas to keep going long after I am ready to head in for the day. Best horse I have ever owned.
Other good lines to consider are Little Peppy, Doc Bar, Two Eyed Jack, and Driftwood.
A lot of the really good ranch horse lines tend to be on the shorter side: 14.3 - 15.2 so hopefully you are OK with a shorter horse.
Absorb what is useful, reject what is useless, add what is essentially your own. - Bruce Lee