First off; What are you upgrading FROM?
If the current GPU is quite weak:
Right now I'd start saving, but hold off on any solid plans for a little while.
If you don't already know, Nvidia look to be announcing new cards based on the Pascal architecture, possibly during the Computex show at the end of this month/early May possibly a little earlier, so I'd hold fire, at least until then before you hit the 'add to basket' button.
I'd also hold off on the CPU/MB/RAM upgrade, with such a hefty CPU overclock any restrictions on a GTX970 are going to be fairly small (assuming a 60Hz 1080 display), if your display is of a higher resolution the restriction will be even smaller.
If you're as poor as the rest of us, it'll take a while to save enough for either, so use the time to do as much research as you can, because if you're looking months ahead there's little point in getting a parts list together now, because there's always something better 'just around the corner', in this case, AMD is due to (finally) release its own new cards 'Polaris' in a few months as well!