Quick ventures get you "random" stuff apparantly, and is your best bet if you're actively playing for a while. Just drop by every hour and see what they got!
The field ventures....... they aren't so great.. Steady EXP for your retainer while you're gone, but the reward can be the same thing for five+ levels. And yah, it makes no sense why they bring back 2 HQ items after 18 hours. EIGHTEEN HOURS, THAT'S ALL YOU FOUND?!