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
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$46 total
A better fit might be the
Poker X intelli78 is selling.