No, I didn't say that Flurry attacks had to come from all different weapons, I didn't mean to be saying that either. In fact it indicates specifically, that they can come from all the same... or all different... as the monk chooses. (as long as they are all monk weapons/eligible) What I was trying to point out was that a monk does either their weapon damage, or their unarmed strike damage. All the feat does, is bump up one of their natural weapons, up to the same damage that they could have done without it in the first place.
If you read the claw blades (at least as presented in the SRD) they change the attack from a Natural Weapon to a Light Slashing Weapon, which would mean they would be eligible for being made made masterwork, and eligible for being enchanted, but would no longer be Natural Attacks, so not eligible for the benefits of the discussed feat. It does indicate that Catfolk with the claws racial trait are considered proficient with that weapon however, but they aren't natural attacks any longer. (I verified that the PRD wording is the same. See below with my emphasis.
PRD:
Claw Blades: These subtle blades can only be used by catfolk with the cat's claws racial trait. Bought in a set of five, they fit over the wearer's claws on one hand. The blades grant the wearer a +1 enhancement bonus on claw attack rolls with that hand and change the weapon type from a natural weapon to a light slashing weapon. Catfolk with the cat's claws racial trait are proficient with this weapon. The claw blades can be enhanced like a masterwork weapon for the normal costs. The listed cost of the item is for one set of five claws for one hand.
Also the Feral Combat Training feat talks about picking one of your natural weapons, not one type or group of your natural weapons. I'm not certain I'd normally be that finicky about things in general... if it didn't seem overpowering and made sense in general. But if someone is trying to pull use some 'form' to get them more attacks than a flurry normally allows, and claiming all their attacks get to use their monk damage and tap extra powers on top of that too, I suspect I would be looking back at this portion and seeing if it has pushed it too far.