The Radeon 6670 does not require additional power, so it only has 75W available to it through the PCIe slot. I think the TDP of the card is something like 66W. I'm running one with a 2500K (all stock clocks) on a 150W PSU.
The AMD CPU will take more power, so you'd probably want at least 200W of good +12v power.
Newegg has 300W Seasonic PSUs for around $45 that would work well.
The best way to future-proof is to save money and spend it on future products. (Ken g6)
SSD turns duds into studs. (JBT)