First off, the Ruger SR9 is a fine pistol. An ex-girlfriend purchased one to replace her Taurus wheel gun and she and I both fell in love it.
They're both gone now.
But in regards to the OPs 9mm triangle, I would recommend the Glock out of the three if it is to be the first defensive handgun and primary handgun.
Plenty of after market support, spare mags, holsters etc. The design is proven and effective.
However, and this is my more esoteric side speaking, I think the Ruger P-95 is a pretty neat gun. Mine is utterly reliable and digests anything I feed it.
That being said, there is no reason for the gun to be limited to 10 rnd OEM magazines other than old Bill's stupidity.