Someone has probably done one of these before, but this is my version :)

32 x 32

also, texture pack is the monkeyfarm version of john smith.

have tested several height builds, you can build this at the building max (green stem touching build ceiling), still visible from about 65 with render distance set to far. with a mid range render, its best built with the stem touching at about block 220 in my opinion, visible to most players on the ground relatively quickly.