Sorry, but I feel like I came into the middle of a conversation. I see that you have a CB750K7 and note that you want to modernize the rear and the front, but you also say you want a classic café look. I gather from this that what you're really going for is a restomod café and not a period-correct (classic) café. Is this going to be a showbike, street bike, vintage-ish racer?
Lots of members here have done modern fork swaps. Some have also upgraded to a CalFab aluminum swingarm (from MotoGP Werks), Dresda (period correct) boxed swingarms, TTR400 swingarms, or CMR chromoly boxed swingarms.
What's the story the swingarm and rear wheel/brake set-up pictured in your post?