Well, if I could make a suggestion on getting the Mannequin parts... Why don't you raise your SMN to about lv 20, get Ramuh (sp?) and do the Horlais Peak BCNM 20 - Shooting Fish Solo?
If you check the page for that BCNM on here you can see various stratgies used by different SMNs... I actually know a few Smns who make thier gil this way.
All it takes is time, patience, beastman seals, and a little luck.