I'm going to post up a couple of designs from work in a bit. I think I've learned something from this thread too - in that Long Range, Accurate Plasma barbettes (Tl 14 barbettes) are my new favourite.
Wraith - 40 ton space superiority fighter - mass production version
Type.....................................................Cost (MCR)..........Weight
Hull Size: 40 tons S4–Streamlined, Stealth.........5.54..................-40
Armour Bonded Superdense (15) TL15................2.77...................5
Drive Gravitic-M sT (TL 10)......9Gs...................28.6.................12.35
Power Plant Fusion sT 9 Rating..........................20....................8.7
Power Plant Fuel Fusion Fuel sT (1 Day)......................................0.3
Cockpit - Holographic Controls..........................0.25.................1.5
Basic Military Sensors (Radar, Lidar, Jammers, +0 DM)...1.................2
Reinforced Hull.........+3 hull.............................0.4...................4
Fire control ...................................................1.....................1
Plasma Barbette (TL-14)Accurate and Long Range.....10.....................5
Computer Model 5....25 Rating Max...................10.......................0
Fire Control/3...............................................6........................0
Evade/1......................................................1.........................0
Totals........................................................86.56...................0.15
Stats: 9g, 4 Hull, 1 Struct, 15 Armor, Long Range & Accurate Plasma Barbette
Spectre - 40 ton space superiority fighter - Aces-only-because-im-expensive version
Type.....................................................Cost (MCR)..........Weight
Hull Size: 40 tons S4–Streamlined, Stealth.........5.54..................-40
Armour Bonded Superdense (15) TL15................2.77...................5
Drive Gravitic-M sV (TL 12)......10Gs....................60.................11.25
Power Plant Fusion sV (TL 15) 10 Rating..................48.................7.425
Power Plant Fuel Fusion Fuel sV (1 Day)......................................0.3
Cockpit - Holographic Controls..........................0.25.................1.5
Basic Military Sensors (Radar, Lidar, Jammers, +0 DM)...1.................2
Reinforced Hull.........+3 hull.............................0.4...................4
Reinforced Structure...+1 struct........................0.4....................2
Fire control ...................................................1.....................1
Plasma Barbette (TL-14)Accurate and Long Range.....10.....................5
Armoured Bulkhead-Barbette?...........................0.1.......................0.5
Computer Model 7....35 Rating Max...................30.......................0
Fire Control/5...............................................10.......................0
Evade/1......................................................1.......................0
Totals......................................................170.46...................0.025
Stats: 10g, 4 Hull, 2 Struct, 15 Armor, Long Range & Accurate Plasma Barbette with armored bulkhead
As you can see, literally double the price for 1 more G, 1 more Structure, and a bonus of +2 to hit. Thats what you're trading for a whole second fighter of the same type
First fighter only has TL 15 for armor. Second fighter has TL 15 for armor and for light-weight Fusion Power Plant.
Original Designed these fighters (Wraith and Spectre) as Zhodani fighters (due to their fighter heavy doctrine) and the availability of TL 15 to Zhodani Military units. But they obviously can be used for any star-empire.