I could work up an RTWO-based VCO based on work I did at MultiGiG some years ago. I'd need to be careful not to cross the MultiGiG patents which are now held by Analog Devices, but I think it's easy to come up with something based on the original MultiGiG white papers. But it's probably best just to find somebody who is familiar with L-C tank oscillator design to whip up a VCO design.