Your camera with work with the following flashes, SB-400, SB-600, SB700, SB800, SB900 and the SB910 but the last three are much larger than the camera itself. The P7000/7100/7700 work with any Nikon iTTL flash but will not work with the older flashes like the SB50DX, SB80DX etc.
Although the P7xxx cameras don't have the facility to control other Speedlights via "Master", I often use an SB-800 set to "Master" (fitted to the flash shoe of my P7000) to control other Speedlights set to "Remote". Works perfectly!
Regards, Clive Liddell Pietermaritzburg South Africa