New to Silent Hunter

[danhall86]

I really want to play a WW2 subsim. Nice graphics are a plus (silent hunter 5 is apparently the forerunner there) as visuals are the most immersive feature to me, but a nice open ended campaign where i can just navigate the ocean sinking things to my heart's content (not without a challenge) is equally important. And ofcourse a healthy dose of realism.

I'm looking at either Silent Hunter 4 or 5.

Which of these two games is the best in it's most recently patched and modded form - both viusally, campaign and gameplay wise.

If I was to go with SH4 or 5, which Modpack is the best to go with to get a definitive experience of each of these titles?

eg. best choice is...
Game: SH4/SH5
Official patches: up to 1.*
Modpack: _________

Ideas of where to start?
I'd get both of the above if I could, but I'm just entering the fray so it's probably wise to start with one, and preferably the one that simmers think is the best SH to date! Thanks