One of the tropes of Traveller and other SF games is that space fighters look like contemporary jet fighters. Why? A streamlined hull is of course necessary if your fighters are to attack a planet with an atmosphere or larger than size 1. Of course there's no clear reason why planetary bombardments and attacks can't be performed by ships in orbit except the Rule of Cool.
Well if you must have space fighters (I know I want mine) you could at least give them a little variety. Look at all those hulls in High Guard for starters. Fighters for surveillance of a star system might use planetary hulls to blend in (unless the locals number their planetoids for such situations.) If you want really long term surveillance stick a low berth on the fighter.
Cheap mass produced fighters might benefit from the cost savings of close or dispersed structure hulls, especially if the main world is a vacuum world or the base ship is used for constant patrols. There's no reason to add 20% cost to a hull. Though it isn't a common image, fighters that have to be used in an atmosphere might be built on a flattened sphere.
A final thought. Most deck plans are designed in a rectangular format. This includes the hangars. That's fine if your fighters are cube-like. A ten meter cube takes up 1000 m^3 and takes up 100 square meters of deck space. A sphere hulled fighter 10 meters in diameter only has ~525 m^3 but takes up 78.5 square meters. That's 3/4 the area for half the displacement tons making it less efficient to store. Plus you'd need restraint devices to keep the thing from rolling around. Cones are even worse, assuming a 10 meter height and five meter radius the ting takes up 78.5 square meters for a volume of 261 m^3. Extremely streamlined hulls like needles could be similar to cones or take up more room due to wings. Wet navy aircraft avoid some of this by having their wings fold up. Smart metal wings could be very useful. Dispersed structures and planetoid hulls could be the worst case. You might want to consider mapping out small craft to get an idea how much deck space they take up or (for sanity's sake) go with modifiers based on the hull type. For example:
Cylinder or flattened sphere x1.25
Close structure x1-2 (ref's call)
Dispersed structure x4 or more (requires the deck to be in zero gee also)
Planetoid/buffered planetoid x4
Or you could just go by streamlining and be less exact, assuming you could find something to fit in otherwise wasted space (fuel, snack cakes, whatever.) Streamlined hulls get stored at their displacement, partially streamlined at 130% of their displacement and non streamlined at 150% of their displacement and get on with your game.
Of course you can avert all of this by having a dispersed structure which sensibly sticks all its subordinate craft on the outside of the hull. Any hangar space would be for repairing small craft without using spacesuits.