Behold the Courser family. All are built on a common forty five ton tracked chassis powered by a 180 rated fusion engine (of hatchetman, blackjack, and javelin fame) and have the required environmental sealing and (limited) amphibious capability.
While most of the vehicles meet their listed requirements well enough (if you're willing to count the ability to carry fragmentation or inferno SRMs as significant anti-infantry capability on the AFV), the self propelled gun only barely squeaks through. The only nod to advanced technology is the CASE on the AFV and IFV (but not on the SPAV because weight).
While I wanted to stick with a common chassis, the 180 engine could also work with a 30 ton tracked chassis (for potential scout vehicles) or a 40 or 50 ton wheeled chassis (which would probably yield a better self propelled gun).
Courser Armored Fighting Vehicle
Introduction Year: 3055
Tech Rating/Availability: E/X-X-D-D
Cost: 1,982,875 C-bills
Type: Courser
Technology Base: Inner Sphere (Standard)
Movement Type: Tracked
Tonnage: 45
Battle Value: 750
Equipment Mass
Internal Structure 4.5
Engine 180 Fusion 10.5
Cruising MP: 4
Flank MP: 6
Heat Sinks: 10 0
Control Equipment: 2.5
Power Amplifier: 0.0
Turret: 1.0
Armor Factor 120 7.5
Internal Armor
Structure Value
Front 5 26
R/L Side 5/5 24/24
Rear 5 20
Turret 5 26
Weapons
and Ammo Location Tonnage
SRM 6 Turret 3.0
PPC Turret 7.0
Combat Vehicle Chassis Mod Body 4.5
CASE Body 0.5
SRM 6 Ammo (30) Body 2.0
Combat Vehicle Chassis Mod Body 2.0
Courser Infantry Fighting Vehicle
Introduction Year: 3055
Tech Rating/Availability: E/X-X-D-D
Cost: 1,775,344 C-bills
Type: Courser
Technology Base: Inner Sphere (Standard)
Movement Type: Tracked
Tonnage: 45
Battle Value: 662
Equipment Mass
Internal Structure 4.5
Engine 180 Fusion 10.5
Cruising MP: 4
Flank MP: 6
Heat Sinks: 10 0
Control Equipment: 2.5
Power Amplifier: 0.0
Turret: 1.0
Armor Factor 120 7.5
Internal Armor
Structure Value
Front 5 26
R/L Side 5/5 24/24
Rear 5 20
Turret 5 26
Weapons
and Ammo Location Tonnage
2 Medium Laser Turret 2.0
SRM 6 Turret 3.0
Machine Gun Turret 0.5
Combat Vehicle Chassis Mod Body 4.5
CASE Body 0.5
Machine Gun Ammo (100) Body 0.5
SRM 6 Ammo (30) Body 2.0
Combat Vehicle Chassis Mod Body 2.0
Infantry Body 4.0
Courser Combat Engineering Vehicle
Introduction Year: 3055
Tech Rating/Availability: D/X-X-D-D
Cost: 1,595,000 C-bills
Type: Courser
Technology Base: Inner Sphere (Standard)
Movement Type: Tracked
Tonnage: 45
Battle Value: 465
Equipment Mass
Internal Structure 4.5
Engine 180 Fusion 10.5
Cruising MP: 4
Flank MP: 6
Heat Sinks: 10 0
Control Equipment: 2.5
Power Amplifier: 0.0
Turret: 0.5
Armor Factor 96 6
Internal Armor
Structure Value
Front 5 20
R/L Side 5/5 20/20
Rear 5 20
Turret 5 16
Weapons
and Ammo Location Tonnage
Lift Hoist/Arresting Hoist Rear 3.0
Medium Laser Front 1.0
Bulldozer Front 2.0
Backhoe Turret 5.0
Combat Vehicle Chassis Mod Body 4.5
Combat Vehicle Chassis Mod Body 2.0
Infantry Body 3.5
Courser Self Propelled Gun
Introduction Year: 3055
Tech Rating/Availability: D/X-X-D-D
Cost: 1,580,500 C-bills
Type: Courser
Technology Base: Inner Sphere (Advanced)
Movement Type: Tracked
Tonnage: 45
Battle Value: 383
Equipment Mass
Internal Structure 4.5
Engine 180 Fusion 10.5
Cruising MP: 4
Flank MP: 6
Heat Sinks: 10 0
Control Equipment: 2.5
Power Amplifier: 0.0
Armor Factor 80 5
Internal Armor
Structure Value
Front 5 20
R/L Side 5/5 20/20
Rear 5 20
Weapons
and Ammo Location Tonnage
Thumper Front 15.0
Combat Vehicle Chassis Mod Body 4.5
Thumper Ammo (20) Body 1.0
Combat Vehicle Chassis Mod Body 2.0