Wanted Small-small/medium mtb frame, disc specific

[raidan73]

My boy has outgrown his 2012 Chameleon so I'm looking for a new frame for him. In an ideal world it'll be something I can transplant the parts from the existing build on to but I'm happy to consider other options. He's about 5'6", so a small or small-medium frame would be suitable, I would think. I'm not overly fussy, as he's not into biking as much as he used to be, but would like something half decent and fairly bombproof. Something from Cove, Ragley, Cotic, On One would all be fine but certainly not limiting it to those brands. An old Evil Sovereign or Dialled Prince Albert would be nice too. I'd also consider a full bike, as long as I could come out of it without a huge negative balance, once the Chameleon is sold. Alternatively if someone can lend me a few grand for a Dawley T16 then he can just have my Chromag, and I'll sell the Santa Cruz!

Here's the current bike setup...

 

[dandy1]

18" too big?

I've an 18" fire mountain that I transfered bits from onto another frame

 

[raidan73]

18" too big?

I've an 18" fire mountain that I transfered bits from onto another frame

Might be. I'm thinking 16" or 17"

Thanks though