I bought my wife a Metz flashgun to use with her D7000, as a spare and for her to try off-camera flash, with her Nikon SB-800 and SU-800. She has not used it extensively, but it seems to work fine. I do not recall the exact model designation, but it is the one comparable in power to the SB-700. The control buttons seems simpler and more intuitive than a typical Nikon flashgun.
I have a Nissin Di 866 II Professional, to fit Canon. It is quite capable and powerful. One desirable feature is that when the camera is turned 90 degrees to portrait oriention, the display screen rotates, in order to be read more easily.
Canon 7D2/7D/5D/40D/1D2N/M3; Nikon F6/D700/FM3A/1Dx/Coolpix A; Canon 40mm 2.8 STM, 135L, 50L, 35L, 50mm 1.8 I, 100mm 2.8L Macro, 10-22mm EF-S, 400mm 5.6L, 16-35mm 2.8L II; Nikkor 50mm 1.2 AI-S, 50mm 1.4G, 50mm 1.8D, 16mm 2.8D Fisheye, 180mm 2.8D, 100-300mm 5.6 AI-S, 45mm 2.8 AI-P, 14-24mm 2.8G, 24-70mm 2.8G, Micro-Nikkor 60/2.8G; Voigtlander 90mm f/3.5 SL II, Zeiss ZF.2 2/135 APO