There is a Great Soul Arrow in FoFG. In the trap room with all the ballista IIRC. Then there is a Soul Spear in Huntsman's Copse.
Your first destination really ought to be No Man's Wharf though so you can access Carhillion who sells various spells. --- "Stand amongst the ashes of a trillion dead souls and ask the ghosts if honor matters." PSN ID: FatBeezzee (no blank invites please)