Forgive me for my ignorance but I'm not sure what you mean by "SR"?
In any case, to meet people of Plutonian and Neptunian nature to me would mean to meet people who have a well aspected Sun, Moon sign or emphasis in there natal chart around zodiac signs that are ruled or heavily influenced by the energies represented symbolically by these 2 planets. In other words, ask yourself, what zodiac signs are ruled or co-ruled by Pluto and Neptune? therein, you will have your answer.
Depending on your acceptance of different schools of thought on astrological rulerships in so far as constellations are concerned, it could be that Pluto is associated with Scorpio and Neptune is associated with Pisces. These 2 planets seem to fit the archetypes of Pisces and Scorpio, however some astrologers will argue otherwise.