This runs into one of the issues I have with BT's aero construction rules, because ships like the one you describe(in particular: 2/3 movement speed but high durability) should be legal, and they aren't. 2/3 is capped at 90 SI, which is very low for a custom-built ship. As such, I'm going to design a ship that is not technically legal - its structure is double what the official rules permit. (If you want to change it to 3/5 and 150 SI, you need to cut about 60,000 tons, FYI - cut the Gauss mounts and you're basically there, then just tweak the cargo to fit.)
Also, I can't remember exactly what tech base you're using here. I went with good-but-not-great tech across the board. Each broadside has 24 NAC/30, 4 HNGauss, and 8 HNPPC, and the nose and aft each have 8 HNPPC. There are also 8 NL/55 and 4 AMS in each of the major arcs. Support craft are 36 fighters, 6 shuttles, and 4 DropShips. And it has a pretty respectable cargo bay and fuel supply, too, plus a large NCSS.
Class/Model/Name: Falke Battleship
Tech: Inner Sphere
Ship Cost: $19,510,937,600.00
Magazine Cost: $381,600,000.00
BV2: 287,897
Mass: 2,000,000
K-F Drive System: Compact
Power Plant: Maneuvering Drive
Safe Thrust: 2
Maximum Thrust: 3
Armor Type: Ferro-Carbide
Armament:
48 Naval AC 30
32 Naval PPC Heavy
48 Naval Laser 55
24 AMS (IS)
8 Naval Gauss Rifle Heavy
Equipment: Mass
Drive: 240,000.00
Thrust
Safe: 2
Maximum: 3
Controls: 5,000.00
K-F Hyperdrive: Compact (39 Integrity) 905,000.00
Jump Sail: (8 Integrity) 130.00
Structural Integrity: 180 360,000.00
Total Heat Sinks: 8124(16248) Double 7,387.00
Fuel & Fuel Pumps: 15000 points 6,120.00
Fire Control Computers: 0.00
Armor: 5868 pts Ferro-Carbide 7,200.00
Fore: 1000
Fore-Left/Right: 1000/1000
Aft-Left/Right: 1000/1000
Aft: 868
Dropship Capacity: 4 4,000.00
Grav Decks:
Small: 0.00
Medium: 2 200.00
Large: 0.00
Escape Pods: 60 420.00
Life Boats: 60 420.00
Crew And Passengers:
100 Officers in 1st Class Quarters 1,000.00
345 Crew in 2nd Class Quarters 2,415.00
148 Gunners and Others in 2nd Class Quarters 1,036.00
102 Bay Personnel 0.00
# Weapons Loc Heat Damage Range Mass
8 Naval AC 30 FL 800 2400 (240-C) Long-C 28,000.00
8 Naval AC 30 FR 800 2400 (240-C) Long-C 28,000.00
8 Naval AC 30 AL 800 2400 (240-C) Long-C 28,000.00
8 Naval AC 30 AR 800 2400 (240-C) Long-C 28,000.00
8 Naval AC 30 LBS 800 2400 (240-C) Long-C 28,000.00
8 Naval AC 30 RBS 800 2400 (240-C) Long-C 28,000.00
8 Naval PPC Heavy Nose 1800 1200 (120-C) Extreme-C 24,000.00
8 Naval PPC Heavy Aft 1800 1200 (120-C) Extreme-C 24,000.00
8 Naval PPC Heavy LBS 1800 1200 (120-C) Extreme-C 24,000.00
8 Naval PPC Heavy RBS 1800 1200 (120-C) Extreme-C 24,000.00
8 Naval Laser 55 Nose 680 440 (44-C) Extreme-C 8,800.00
8 Naval Laser 55 Aft 680 440 (44-C) Extreme-C 8,800.00
8 Naval Laser 55 FL 680 440 (44-C) Extreme-C 8,800.00
8 Naval Laser 55 FR 680 440 (44-C) Extreme-C 8,800.00
8 Naval Laser 55 AL 680 440 (44-C) Extreme-C 8,800.00
8 Naval Laser 55 AR 680 440 (44-C) Extreme-C 8,800.00
4 AMS (IS) Nose 4 12 (1.2-C) PDS 2.00
4 AMS (IS) Aft 4 12 (1.2-C) PDS 2.00
4 AMS (IS) FL 4 12 (1.2-C) PDS 2.00
4 AMS (IS) FR 4 12 (1.2-C) PDS 2.00
4 AMS (IS) AL 4 12 (1.2-C) PDS 2.00
4 AMS (IS) AR 4 12 (1.2-C) PDS 2.00
4 Naval Gauss Rifle Heavy LBS 72 1200 (120-C) Extreme-C 28,000.00
4 Naval Gauss Rifle Heavy RBS 72 1200 (120-C) Extreme-C 28,000.00
Ammo Rounds Mass
Naval AC 30 Ammo 4800 3,840.00
AMS (IS) Ammo 6240 520.00
Naval Gauss Rifle Heavy Ammo 800 400.00
Equipment Mass
Bay Fighter 36 5,400.00
Bay Small Craft 6 1,200.00
Cargo, Standard 75000 75,000.00
NCSS Large 1 500.00