Yeah, armor's the problem. Especially if you want anything more interesting that a single light missile launcher alongside the AC and MLs...
Here's a modified Champion that reaches almost Dragon-style armor with slightly more mixed armament:
Champion CHP-2L
Mass: 60 tons
Tech Base: Inner Sphere
Chassis Config: Biped
Rules Level: Introductory
Era: Age of War/Star League
Tech Rating/Era Availability: D/C-E-D
Production Year: 2750
Cost: 4 916 800 C-Bills
Battle Value: 1 078
Chassis: Unknown Standard
Power Plant: Unknown 300 Fusion Engine
Walking Speed: 54,0 km/h
Maximum Speed: 86,4 km/h
Jump Jets: None
Jump Capacity: 0 meters
Armor: Unknown Standard Armor
Armament:
1 Autocannon/10
1 Medium Laser
1 SRM-4
2 Machine Guns
Manufacturer: Unknown
Primary Factory: Unknown
Communications System: Unknown
Targeting and Tracking System: Unknown
================================================================================
Equipment Type Rating Mass
--------------------------------------------------------------------------------
Internal Structure: Standard 99 points 6,00
Engine: Fusion Engine 300 19,00
Walking MP: 5
Running MP: 8
Jumping MP: 0
Heat Sinks: Single Heat Sink 10 0,00
Gyro: Standard 3,00
Cockpit: Standard 3,00
Actuators: L: SH+UA R: SH+UA
Armor: Standard Armor AV - 152 9,50
Internal Armor
Structure Factor
Head 3 8
Center Torso 20 23
Center Torso (rear) 5
L/R Torso 14 18
L/R Torso (rear) 5
L/R Arm 10 15
L/R Leg 14 20
================================================================================
Equipment Location Heat Critical Mass
--------------------------------------------------------------------------------
Autocannon/10 RT 3 7 12,00
Medium Laser LT 3 1 1,00
2 Machine Guns RA 0 2 1,00
SRM-4 LA 3 1 2,00
@AC/10 (10) HD - 1 1,00
@AC/10 (10) RT - 1 1,00
@MG (1/2) (100) RA - 1 0,50
@SRM-4 (25) LA - 1 1,00
Free Critical Slots: 36
BattleForce Statistics
MV S (+0) M (+2) L (+4) E (+6) Wt. Ov Armor: 5 Points: 11
5 2 2 0 0 3 0 Structure: 5
Special Abilities: SRCH, ES, SEAL, SOA, AC 1/1/0
A real tinderbox too, with all that ammo! #P