My party (no class change) was:Male Rawulf Lord - a lot of HP, good Armour/Weapons, Divine spells.
Male Dwarf Monk - KIA, Psionic spells, Nice AC
Female Elf Valkiry - a lot of HP, good Armour/Weapons, Divine spells.
Male Felpurr Samurai - KIA, Mage spells, decent Armour/Weapons, I like to have a samurai in the party
Male Hobbit Ranger - a lot of HP, decent Armour/Weapons, Alchemy spells, Thief & Locksmith. If you apply ranged weapons patch, he could be a killer, but I played without.
Female Faery Bishop - good mana regen, -2 natural AC, Divine & Mage Spells
I managed to kill all the gorrors around level 60. I killed them on expert difficulty level (two gorrors per fight). Only BEAST had killed my samurai once during the battle - this was the only casualty.
During the game I constantly changed weapons to develop as much allowed skills for each character as possible.
This was a real fun.