I'm a big fan of using my straight and angled air-grinders, with a 3" cutoff wheel. The air bodies allow you more flexibility than an electric, and air is more forgiving if you dig the wheel in -- less kick. That said, a torch works great in many places, especially if you have the motor out and can blast merrily away.

The rear lower control arm mounts are comprised of what sems like three separate stamped-metal layers that appear to be welded on in sequence. Using a torch is tough here because of the way the flame or plasma arc deflects internally, so if you do choose to torch, leave yourself a half inch or so of standoff from the frame. It is much easier to dress the frame letter with a grinder than it is to patch-weld holes you've inadvertently gouged in the frame.

Randii