The 460 is the better buy IMO.
The 560 Ti is basically a GTX 460 with the last cluster of shaders unlocked.
well the 560ti can't even completely max out bf3, if you plan for 1080p max shading AA and AF then you aren't going to get as far as you hoped, bf3 looks the way it does for a reason, it takes a monster to max
don't think it can max it out at 1080 with ~60fps constant, and also don't add a second gpu if that was the plan and idk if enermax is a good brand so that might need to change at some point
well i've never really heard of enermax so couldn't say they were good so i said idk about the brand, good to know though.