I have some of what you're looking for, but I'm not sure it's a good fit.
I have a Pure PCB, I have MX-Blue switches and I have a set of Pure key caps, but they are ABS, not PBT.  

 In case you're interested, the prices are below:
     $25 = Pure PCB
     $16 = 65 MX-Blue switches
     $05 = Pure Stock Key Cap Set
     ------------------------------------
     $46 total 
A better fit might be the 
Poker X intelli78 is selling.