In my experience the AI construction vehicles file only use the default design type.
Default AI
Design Type -
Attack Ship, Defense Ship, Attack Base, Defense Base, Base Space Yard,
Cargo Transport, Troop Transport, Carrier, Colony (Rock), Colony (Ice),
Colony (Gas), Mine Layer, Mine Sweeper, Boarding Ship, Open Warp Point,
Close Warp Point, Create Planet, Destroy Planet, Create Star, Destroy Star,
Create Storm, Destroy Storm, Space Yard Ship, Mine, Satellite, Weapon Platform,
Troop, Fighter, Create Black Hole, Destroy Black Hole, Create Nebulae,
Destroy Nebulae, Satellite Layer, Kamikaze Attack Ship, Recon Satellite,
Anti-Ship Drone, Anti-Planet Drone, Drone Carrier.
But if you want a long range attack ship and a missile attack ship in the AI design creation file, try this.
Colonial AI Design Creation File- Colonial Republic by TNZ
Name := Gunstar
Design Type := Attack Ship
Vehicle Type := Ship
Default Strategy := Optimal Firing Range
Size Minimum Tonnage := 10
Size Maximum Tonnage := 2000
Num Must Have At Least 1 Ability := 1
Must Have Ability 1 := Weapon
Minimum Speed := 4
Desired Speed := 4
Name := Strikestar
Design Type := Defense Ship
Vehicle Type := Ship
Default Strategy := Optimal Firing Range
Size Minimum Tonnage := 10
Size Maximum Tonnage := 1400
Num Must Have At Least 1 Ability := 1
Must Have Ability 1 := Weapon
Minimum Speed := 4
Desired Speed := 4