Stock for stock, the G860 will likely be about as fast as the Phenom and use less power. However, in heavily threaded games/apps, the Phenom will likely be faster. If you decide on the Phenom, get a good board (970,980 or 990 chipset) so you can later upgrade to an FX63xx or FX83xx CPU. Also, the Phenom is easily overclocked to 4.0+Ghz or better (mine was stable at 4.336Ghz). A Phenom 965 at 4+Ghz is performance wise about the same as a lower end Sandy Bridge I5.
The Intel route is basically a dead end. As Haswell chips will be coming out soon but that could also drive prices on Ivy Bridge down (very unlikely as Sandy Bridge held it's prices for several months after IB).