Majority of Left Hand rifles are push feed, which is ok but I prefer CRF, I have a Winchester M70 "Safari Express" 375H&H and a Winchester M70 in 30/06, but to get a .308Win length rifle in CRF is very hard, I think you have 3 options

I would go with Granite Mountain Arms action and custom make what you want.

Find a Lefty Winchester 30/06...270 and make do with the long action and calibre.

Get a push Feed, quite a few makers.

Cheers
Steve