I'm working on something similar to this, I think. I'm building what could effectively be a bank of 4 complex VCO's by combining some dual oscillators with some signal minglers.
I have built 4 2VL1's by Weston Audio, which is a dual oscillator plus a LFO in a tight 10hp package. I'm planning on combining these with 4 Mutable Instruments Warps, which acts as the 'signal mingler' component of a complex Oscillator, and is capable of FM, AM, and many other modulations. There is a small 8hp version of this module out there called Twist that I'm planning to use. I have those modules together with a 4x4 buffered multi to handle feeding CV inputs to multiple Oscillators at once and an octal VCA to handle output. The plan of course is to use the module as one component in a larger system. While the 2VL1 lacks a true sine wave option, I really like its construction and size factor. I'll be pumping all of this plus a power supply module into a 1-row 104hp package.
I asked about viable complex oscillators elsewhere but found there wasn't much out there beyond the obvious options such as the Rossum Trident and Make Noise DPO, etc, and there was not much at all as far as DIY options, which is what I was interested in. Someone turned me on to the MU Warps in that conversation. I thought I had oggled the entire line of MU products, but several had apparently gotten past me (such as the truly amazing Edges). I'll be acquiring my 1st Warps at the end of the month, and will be getting 3 more if the results are good.
Here is the current plan for my project:
