You cannot customise the ships in SS08. They are designed to be realisticly handling, so you cannot change the dynamics.
You can not change the appearance of any of the vessels, apart from the P6 patrol boat. If you use the search button to search for 'P6 Skin' you will probably find some.
Lights can be edited, but only by those who know what they are doing. The lights are hosted at;
http://schiffsim-welt.marcnet.eu/Forum/ (http://schiffsim-welt.marcnet.eu/Forum/), in the English forum (you must register, it appears that it has been made harder to sign up since I did it.)
Horns can be edited, simply replace 'horn.wav' with an identically named .wav file to change the horn.
There are superpacks available at the Amazing Forum.
HI ALL
you will now find all super packs for shipsimulator 2008 at the new forum
AMAZING FORUM • http://www.amazing-forum.com/
look forward to see you as member
Here you will find all sort of things free games and more
On this forum you will find super pack's, missions, free games free ships to ss 08 and more
welcome to AMAZING FORUM •
Tore
These superpacks feature new lights, dynamics, connections for containers e.t.c.