Hi all I am looking at replacing my AmiDock but don't know which alternative to use,  I have been looking at PolyNetNG but I cant seem to find a pic of the 68k version anywhere but I want to have a look at what it looks like on OS 3.9 before I install It ?

It doesn't need much installing, just unpack the archive for example to ram: and run it from there to try it yourself.

I think PolynetNG is MOS only.
you might check pixload4 instead http://obligement.free.fr/articles/pixload4.php

EDIT: here you have a screenshot https://web.archive.org/web/20081111082307/http://polymere.free.fr/

PolyNet NG has working homepage still, you don't need to go to wayback machine.
http://polymere.free.fr/Site_New/polynet_en.html

It has the same screenshot there, which I think is from the MorphOS version, but as you can see on both pages there's older 68k version available too.

So does it look exactly like the MorphOS Screenshot when installed on AOS 3.9? I really don't want to install in case it looks uglier than amidock and then I'm stuck with

As I said, you don't need to _install_ it, just unpack and try, and forget it if it doesn't do what you want, no need to stuck or uninstall or any extra work by that. But of course you need to look the configuration options to see if it does what you want.