I think whichever fight happens GSP/Silva or Silva/Jones, I believe Silva wins them both.
However on paper anyway, I don't think either should be a walk in the park. If Silva has a weakness, it's being up against & taken down by good wrestlers. GSP's wrestling & top control is the best in MMA. Jones's wrestling isn't exactly weak either & while I'd say his top control maybe isn't as strong as GSP's, he does tend to do alot of damage in short periods on the ground with those short ass elbows he throws. + Jones would outweigh Silva & I would presume would be stronger.
Silva is technically & power wise a far better striker than both.
Both fights would come down to weight, height & reach I feel. People would be foolish to just write GSP off against Silva, while he will undoubtedly be outweighed on fight night by Silva, the height & reach advantage Silva has wouldn't be a million miles away from what GSP faced against Condit & due to the fact GSP is so explosive with his kicks, punches & takedowns, GSP's speed would be something that could balance things up a little on the feet from a physical aspect.. not so much a technical as striking is where Silva is at home.
Both fights are very intriguing & while I feel Silva would be favourite to win both, you'd be foolish to write either GSP or Jones off coming up against him.