Unlike years ago when only a few manufacturers offered left hand bolt rifles, today you have a much wider selection. As stated, you can get a lefty in Ruger, Browning, Savage, Remington and others in the chamberings you mention. You can also go the single shot route from T/C, Ruger #1, H&R, etc. It all depends on how much you want to spend. My lefties are from Savage, Browning and Remington. I've owned Rugers too.
For a basic down to earth hunting rifle that is accurate and reliable, its hard to beat the Savage 111FL in the 30-06 or 270. I go with the '06 is I could only get one.