It has 2x6 and 2x6+2, so it has the connectors if you xfire 6870s (it was unnecessarily hard to find this info, I'll give you that). I say go for it. It has fair reviews. Nice find.
My only concern is that it splits the 12v rail, so you have 30 amps going to the mainboard and peripherals and 30amps going to the video cards. I suppose that's enough for 6870s, but you might want to double check that.
don't know much about what he was talking about here... so I need you help on this
Will it be able to SAFELY crossfire 2 6870s plus overclocking the 2500k?
I think HEC, the OEM for the Xigmatek NRP-PC702, has the two +12 V rails distributed as follows:
+12V1: Main motherboard ATX 20+4 Pin cable, a PCI-E video card cable with one PCI-E 6+2 Pin connector and one PCI-E 6 Pin connector, two cables with four SATA connectors on each cable, two cables with Molex 4-pin peripheral connectors and FDD connector
+12V2: The ATX12V/EPS12V 4+4 Pin Connector cable and a PCI-E video card cable with one PCI-E 6+2 Pin connector and one PCI-E 6 Pin connector
The Xigmatek NRP-PC702 has a combined +12V continuous current rating of 54 Amps.
AMD recommends that a system with two Radeon HD 6870 graphics cards in 2-way CrossFireX mode should use a power supply with a minimum of 600 Watts or greater with a minimum combined +12 Volt continuous current rating of 37 Amps or greater and with at least four 6-pin PCI-E Supplementary Power Connectors.
The Xigmatek NRP-PC702 exceeds the minimum requirements and should have no problem powering a system with two Radeon HD 6870 graphics cards in 2-way CrossFireX mode. There is sufficient capacity for you to do all the overclocking you may want to attempt.