A linkshell mate of mine got 15000 seals from trading in Black Ghosts and Iron Scutums (i think), and doing a few hours worth of Company leves @ Halatali. The 15 minute ones suck, but some can be completed + handed in in 5mins... They are under random generators like everything else in this game. ><

Like you said the gear isn't all that, he just bought the Flame Sergeants Sash, 2 crafter rings, and the +18 craftsmanship pants.