[sdiy] polyphonic synthesis

[Seb Carr]

I recently became interested in the idea of building analogue synths, but 
through my research on the internet, all kits, modules and schematics are
for monophonic synths.
    whilst i know monophonic synths have a unigue sound and can be played
differently to  polyphonic synths, i am still more interested in building a
poly synth,
    But, i understand that poly synths are far more complex.  Would i be
correct in saying that a poly synths needs  ( at least ) 1 VCO per note of
polyphony?  I read that you would also need a VCF and a VCA for each note,
but surely the synth could be simplified so as the individual oscillatos wer
combined and then put through a single VCF and VCA?
    So, are poly synths actually pretty much out of reach of the home
builder?
Also does anyone know of any kits or pcb's available for a polysynth? (In an
ideal world a polyphonic fatman kit or something, with a switchable
monophonic unison mode).
    Also, do Oakley synths, or any others have any plans for a poly synth
module?

thanx

Seb Carr