My recommendation would be to start out with a base platform that will allow for the greatest flexibility/improvement in the long run.
That generally means spending more money on the core components now (CPU/Motherboard) and bite the bullet and possibly go for a mid-range video card for now. The reason for is simple: It’s far easier to swap out/upgrade your GPU/Video card than it is your CPU/Motherboard. It’s a way of future-proofing your system. If you paint yourself into a corner now by skimping on the CPU and spend more money on the GPU, a year or two down the road, you may want to upgrade your GPU, but may find that your current CPU/Motherboard is holding you back. (Ie. Say you want to get a second video card, but your chipset only supports 2x PCI-E x8/x8 and not 2x PCI-E 16x/16x. In simpler terms, that would essentially hinder performance on your video cards, meaning a less substantial upgrade and possibly even a waste of money).
For example, my PC is currently running an i7 920 overclocked to 3.6ghz, and never once has it throttled my video card or anything else. It holds its own with even modern hardware, even though it’s a 6 year old CPU. The only upgrade I do is I pop in a new video card every once in a while and I’m good to go. The initial investment of the i7 920 has lasted me 6 years, and by the looks of it, it may last me another year or 2 before a sizable upgrade comes along.