Thanks for an interesting program!

I had some free time and I redrew all the icons in one style.
In three colors (white, black and blue) and in two sizes (64x64 pixels and 128x128 pixels).

In addition to the main icons I redrew icons for CustomUI | AddOns from Max Smirnov's MoI scripts (http://moi.maxsm.net/item/46)
To use them you need to update CustomUI assets.
I will attach files which I changed.

I can't test icons in version 4 because I use 3.2 trial version.

BACKUP ORIGINAL FILES!!!

Select size and color for the icons and put them in these folders:
64/black/ui > moi/ui
64/black/ui/icons > moi/ui/icons

BACKUP ORIGINAL FILES!!!

CustomUI
Extract files from the CustomUI-modified.zip archive > moi/ui/customui