The first and absolutely essential thing you need is the official Ubi 1.1 patch.
http://www.subsim.com/radioroom/down...?do=file&id=66
Next you need the unofficial patch that fixes the problems the official patch didn't, mainly making DC and SH2 work together properly.
http://www.subsim.com/radioroom/down...?do=file&id=67
Then just go down the list here:
http://www.subsim.com/radioroom/down...p?do=cat&id=46
The Vickers mods in the Graphics section make a huge difference.