Here's what you need (in total) for all 5 quests:

Snickerfang jowls - 2
Blasted Boar Lung - 4
Scorpid Pincher - 5
Baslisk Brain - 11
Vulture Gizzards - 14

The vulture gizzards are the hardest, as there are very few mobs that drop those, but the drop rate is something between 10 - 33 % ( in my case, about 20%).

The way I did it was start at the questgivers, and run a clockwise circle around the mountains just south of there, killing everything in my path that was needed. It took me two circles to get the pinchers and jowls.

Then I headed east from the quests until I got to the basilisks, and did the same thing in reverse - at some point you have to run the gauntlet between the DuneMaul Compound and a Shadowstorm camp - just keep to the middle and keep running if you don't think you can handle them on your own.

Took me 2 hours, but I finally managed to get everything. Even picked up a piece of imperfect Dranite crystal for the ""greedy guy"" (can't think of his name) off one of the vultures.

The different effects DO NOT STACK, so turn them in as you complete them. That way you'll have a guardian effect on you for the next hour (or unless you die), and can do other quests in the meantime.

Total time in my case: 2 hours, went up 48 % at level 52, picked up a nice pair of boots from Mr. Greedy when I turned in the crystal, and netted a little over 3 gold after repairs and selling off unneeded items.

If you don't like to grind, then don't pick up the buzzard quests - the rest of them are pretty easy. Plenty of mobs and decent drop rates.

Hope this helps!