Although there are many of them out there, wood foundations can be problematic. Cheaper, yes, but quite possibly not so in the long run. Water (and the tiny wood-eating critters it can harbor and/or encourage) and wood are not good combinations for a firm and long-lasting foundation member.
Before I'd spend money on a wood foundation wall repair, I'd rip out the old and form/pour a new reinforced concrete wall. If the existing footing is OK, all that much easier to do.