I was thinking along these lines for a Japanese raider. Mixed diesel/turbine propulsion system. Diesel power for 15 knots, steam/turbine installation to take it up to 30 knots. 6x12" 8x5", with the 12x24" torpedoes to give a bit extra. 3-4 aircraft for spotting/search missions.
Displacement: 17500 standard, 22,000 tons full load
Dimensions: 633 x 82 x 26 feet
Machinery: 2 shaft, Diesels 15,000bhp, 2 shaft, Steam turbines 65,000shp
Speed: Max 18 knots on diesels only, max 31 knots on both.
Endurance: 14,000 at 15 knots
Armour: 6" belt, 3" deck, 7" turrets
Armament:
6 x 12" (2x3)
8 x 5" (4x2)
16 x 25mm (4x3 4x1)
Torpedoes: 12x24" (1 set of reloads 12)
Aircraft: 3-4
Crew: 950