Sakos, Tikkas, Heym and Sauer all make good left hand rifles. Remmingtons are also solid but need some tweaking - possibly better to spend a bit more. Concentrate on left hand, rather than calibre per se. And don't be talked into buying a right handed rifle - They are just awkward. Ok on the range but in the field off sticks you need the controls on the correct side. And Cz do a good lh 22rf to compliment your centrefire.
If you buy a blaser you can change the bolt from rh to lh. And if you know the right people it won't cost the earth.
as said don't buy right hand. I did. Then along came a leftie and everything had to be replaced. Much better.