You will probably need both a new crank and bottom bracket. If your octalink crank was ruined, I'd expect the bb has suffered as well. You could go retro with Sugino XD and square taper bb or go with a Deore trekking crank with the new external bb. Edit- I see you were planning to use a regular 105 triple. If that gearing suits you, I think you can get new Tiagra with bb for under $100.