Rez:
Umm. How do you get 1d8 damage? It states '1d4'.
Assuming you can't bring yourself to give up Natural Hunter (which is nice... but I'd ditch it if you're serious about this), you pick Natural Weapon as your Ranger fighting style at 2nd level. Take the bonus feat Aspect of the Beast and choose claws. This is a 1d4 attack.
At third level, take Catfolk Exemplar and choose Sharp Claws. This bumps the damage to 1d6. At fifth level, choose Improved Natural Attack. Your claws become 1d8.
Claw blades are actually kind of meh because they force you out of using them as natural attacks. You're better off with the Amulet of Mighty Fists, which gives your natural weapons an enhancement bonus (or flaming, etc).
At a certain point, Claw Blades and TWF feats become appealing again, though, as your BAB and iterative attacks go up. The only real reason to focus on claws is to get the Pounce ability and be able to full attack on a charge. The best way to get there is probably as a TWF ranger, taking claws as a racial ability and then using claw blades. Six attacks on a charge would be pretty nice.