rear disc brakes on 8 3/4

i have small drums. Still from the Small bolt pattern. And they are worn out already. And before I buy all that drum stuff and redrill to big Bolt pattern or buy big drums I gues it is more efficiant to go with discs. Remember i live in Germany and all the US stuff is almost double the Price you pay ( see also customs, shipping ).
thats why i originally wanted to use the Jeep stuff. but too much too Change and tire moves a bit outwards if i remember right. I have Zero space in my wheel openings.

and yes, i expect a bit improvement also. I like modern stuff :)