After searching the internet for some deckplan for an yt-2400 like this ( http://fc04.deviantart.net/fs23/f/20..._captshade.png ) I found one that I like.
This is the one:

I would like to know how to make one like this from scratch with photoshop. I know I could use this one, but I would like to add some modifications (like change the number of seats in cockpit, add a medical room, delete the names, put the entrance to the turret on the right...).

Do you have any collection of objects like this ones? There was a collection on the Holocron, but I can't find it anymore...
Thank you all!