[sdiy] dual VCFs

[crystal]

as y'all can probably tell by this, my third post tonight, i am about to
start to DIY again (finally).

for my first real project in a few years i am considering building a dual
VCF module with the capabilities for VC Band Width, VCcenter freq tracking
maybe with INVERT option on one VC, and maybe some built in overdrive too.
HP/BP on one, BP/LP on the other.

any comments from those who have done this (or something similar)?

any neat ideas?