I am unhappy with the idea of running a 120MHZ VCO and a 120000400 HZ oscillators on the same board. The isolation between the two must be >100 Db or if any of the 120+400, gets into the VCO, it will jump in frequency to 120+400 and lock there irrespective of the control voltage. It can be done but each oscillator must be built in a screened box with feed through Vcc decouplers and VERY good isolation amps. I would go for two VXCOs, with their frequencies off set about 10MHz or above add their outputs together, then upconvert in a mixer with the VCO. The output will need a tunable filter to remove the VCO - 10MHZ component.
Frank