You can approximate that shape with 3 or 4k easily. Pollies aren't usually the big issue; textures are. Smart usage of textures can also simulate organic shapes quite well. Because of the flatness of the design, you really can do it with less than 8k. Better than most, if not all, first ships i've seen, and certainly better than my first one.
I'm not sure what class of ship that is, but an array of turrets would be nice, as well as maybe adding a distinctive feature to the design. It's currently really bland, and could use maybe a raised section running down the spine, or something. Since that's your first, it only really gets better from here, so I wish you luck!