At two paladin levels, you get a boost to your saving throws based on your Charisma bonus. Once you have that, the next bonus of real interest (as others have mentioned) is the Zeal spell.
So, either take your two fighter levels at 3,4 to get the feats early and open the fighter enhancement lines. Or, push to 14 and take the fighter levels at 15/16.
If you're planning on staying in epic levels for a while (farming epic tokens and comms, earning epic destiny xp for fate points, etc) then you can save your two fighter level for 19 and 20. This gives you a chance to really see how a (mostly) pure paladin plays, and then you benefit from the extra feats during your epic play.