That's a lot of money for things that won't be doing too much- k-member, and do I see new front spindles at the top? I see no point in those besides a little weight savings.
Yep those are good suspension mods, I'd get a STB because it's cheap. Don't spend money on a torque arm unless you just have extra money to blow.
The best suspension mod I did to my fbody was definitely springs and shocks. Went with bilsteins and strano springs, what an amazing ride. Not harsh but still nice and firm with a great stance that wasn't too low. I know you like comfort but you should consider it because your shocks could probably be replaced anyway.