Need help finding o-rings for power steering pressure line fitting

I have a 2000 dodge ram that uses a saginaw style power steering pump. Off topic I know but I'm sure some of you have dealt with the o-ring style fittings. The main pressure fitting needs an o-ring replaced. The o-ring on the fitting not the one on the hose end. Anyone know where I can get one, or can I just use a random o-ring from a jobber kit? I'd rather not buy a whole pump.

O'Reilly sells an assortment on their HELP isle. They include several diameters.