T6 mats
I, too, can’t stand grinding in the open world for these items. Instead I prefer to run dungeons and use the proceeds to purchase the materials from the Trading Post.
Buy T5 and upgrade it in mystic forge
Tekkit’s Workshop
Have you completed Frostgorge and all the Orr maps yet? Doing that will net you a variety of tier 6 creature parts.
Apart from that, all I can suggest is to take a break from dungeons to farm Orr for awhile, or buy the mats off the TP …
I’ve had better T6 drops in five hours of Sunstone Cove than anywhere else in the game. You can get powerful blood, armored scales, and the powerful venom sac there. I know some people like to farm minotaurs or trolls in Frostgorge for blood as well.
Other than that you can do whatever you do to make coin and when you go to collect your proceeds from the TP buy that much worth of your T6 mats. It will be slow progress – but it will be progress. And progress is important psychologically when going for a large ticket item.