For sink tips I never use longer then 6 foot and never shorter then 3 foot and then only on the deepest sink tips and hopefully stained water. I average about 4.5 foot. Now the pound test can very greatly and it depends on what species of bass, structure I'm fishing, line weight -6wt-7wt-8wt-9wt etc, water clairity, size of fly. Sounds like a lot so I just use 15pound flourocarbon for lmb and 6pound flo for smb regardless of the other facters and this has worked for me for 15 years or better.

Top water is even more confusing so I will simplify it again. Weedy conditions use a knot-less tapered leader or straight mono about 15 pound or stronger depending on the rod weight and fly. Example on my 9 weight for lmb weedy areas with a popper I might use 20pound flo or even 25pound. Length for these leaders will be about 7 to 8.5 foot.
The lakes I fish now the most in GA are deeper colder and hardly any weeds but we run in to stripers and wipers often so I use Lefty's leader formula in a 9 or 10 foot leader down to a 10 test tippet for spots and lmb and 6pound when after smb. These leaders are notted and when tied properly have never let me down. Hope this helps