Find the 1.4 compatible mods here:
http://www.subsim.com/radioroom/showthread.php?t=126875
The major mods are:
TM or Trigger Maru...a good balance of realistic and playability
RFB or Real Fleet Boat...leans more to realistic game play.
RSRD or Run Silent Run Deep...historical traffic mod that will work with both TM and RFB. Make sure you load the correct version for TM or RFB.
ROW or Reflections on the Water...enviromental mod.
These are the must haves. On the list of other mods, Foo Skins are great. The modded watch are very cool. There is a boat load of other mods that will work with the major ones noted above. All JSGME ready. Download just the 1.4 patch. That is all you need for now as far as patches are concerned.