What is better (price and looks),

512 Head - 256 Everything else.
Full 512.

Ty

512 has the best quality but is way more expensive.

I personally have a 512 head and a 256 body, but 512 is higher quality especially in more complex sets, but for my cartoon set i don't notice a difference.

In my opinion for a average and good text set + a affordable price,

512x512 head
256x256 body
and others 128x128

Its the best and most comon used.

Or you can go for 256x256 head
and 128x128 all other.

i'd say better buy 512 head and full 128
or go with full 512 ...
that's the best way ...

Is there much difference between 512 & 256 body textures?

512 has 4x the quality of 256 textures.
256 has 4x the quality of 128 textures.