You are fairly limited in your healing.
Normally I'd make a "tank group" using your War, SK, Clr, Sham , +2 but then you have no healers for your 2nd group so maybe:
WAR, CLE, ENC, WIZ, NEC, MAG
SHD, SHM, BRD , BST, ROG, BSK
As far as what you can take out. Shei is by far the easiest...