Sounds good so far. Nothing speaks against a 2003 and the circuit is easy to do. A pre amplifier stage is a must as the pickup
voltage may vary from type to type. Your humbuckers should have an higher output compared to single coils. That's one more
big advantage on humbuckers. The dual coil system eliminates hum and double coils also means double the power, which helps
a lot to push the circuit into overdrive sound
. So, the preamp will be integrated, which will provide a further advantage.
I hear a lot of buzz about component selection etc. Just out of curiosity, if I used "vintage" components, would it aid in achieving vintage sound (even though I'd be using chipamp?) So if I used Carbon comp resistors, a lot of poly film caps (in all places that require <10uF) etc...Would it help?
Rather not. I doubt that someone can hear a difference from resistors. The only thing that might happen is the thermal noise if the resistors are bad quality (cheapo carbon resistors).
Vintage components IMO can not be used to achieve Vintage sound. That's a myth, really.
The coloration of sound heavily depends on the circuit design. Not mainly on the used components.
As mentined before - the harmonics and distortions play the role. Even order harmonics give a warm touch
on the tones, while odd harmonics sound horrible. Polypropylene film capacitors can help to make a circuit
sound Vintage - when they are on the right place. I like to use the "Orange drops". It is not 100% proved,
but they sound a little bit warm. Maybe due to a little cut off at the highs. I dunno, but i like them...
The gain control would be placed where it makes sense. Right at the chip's inverting input (pin2) instead of R1 / R2.
This should allow to adjust the gain of the amp stage and the distortion level from clean to heavy.