You were doing well until the last point

I'd cook 4 double portions of curry, or better still work on your technique and do 8 single portions of 4 different curries. Work on a planning for the week, get your chicken tikka marinading on Wednesday, cooked on Thursday. Dhal cooked in advance.
I've cooked many times for 8 or more and I prefer to have nothing to do on curry night...except frying poppadums, chopping onions, making onion bhajis, cooking bread, hoovering, buying booze....
I'd ideally get all the curry cooking finished the day before, sometimes I do half one night, half the next.
Make 4 curries that look and taste different. In my experience people claim not to like it too hot, but then leave all the creamy sweet dishes and scoff the spicy stuff.