TCF,
not as feasible as you might imagine. Probably achievable in the 80's/90's when the technology was all in engines, airframes and weapons.
The next generation is all about software and systems integration. Its hard enough and costly enough upgrading current F18 and F111 (and somewhat unsuccessfully in the case of the latter) with new western avionics/software, let alone soviet airframes with western systems.
We cannot afford to go it alone with a unique system, we must have commonality with the US.