Request for recommendations - Vector Signal Generator

[QuasiCoherent]

I have a new project in sensing and interferometry that i am trying to bring up... for this, I will need a vector signal generator (as a reference point to test against) that can operate into X-band.  My target frequency is 10Ghz, and I am looking primarily to phase-modulate the waveform.  I am wondering what units (if any) are known to be budget-friendly (<5K USD), particularly those that might have known hackable upgrade paths to enable internal ARB features.  I am expecting most any of these units will also have atleast some IQ inputs externally, but an internal ARB would be nice (if I have no luck, I will buy one of my trusted Siglent IQ ARBs and use that...)

I know 10 Ghz is a lot to ask for, just wondering if anyone had some tips.