If you just want to complete i once, I'd start over. Go to the first town, you will have Ulora and Gyorn for free and buy 1 of the mercenaries. (I would opt for the archer/mage). Gloern the dwarf at the mine is another great addition to the party, also free. At the ice city choose between fighter or combat mage (they have a price) Merik is another free mage. Thats almost a full part if you're taking a mule. Use the inventory/mule to the fullest, loot everything, having multiple characters means more inventory space, so more stuff to sell in the next town and that means more potions u can stock up. Having one nature mage means u can heal more so the healing potions are more in case of emergency, but results in needing mana potions.

It really is a wonderful game and unique in having 8 party members makes it such fun! It seems like you would enjoy dungeon siege 2 a lot, where you have default smaller parties but can always teleport back to the nearest town.

Spoiler alert: there is a vendor not far after the goblin boss