I found you can achieve good diversity in the Mauler series of Mechs. It is a 90 Ton Assault Mech, so it will naturally be slower and less nimble than the Black Knight, but can carry copious firepower and armor.
The Maulers can be specialized to carry up to 4 missiles plus energy and ballistic backups, or up to 6 ballistics with energy and missile backups, or up to 6 energy with ballistic and missile backups. The possible combinations are vast, and it's a great platform for standardizing on heavy/copious ballistics. The are my favorites at the moment :-)
A similar story exists for JagerMechs, but they are 65 tons and can be fragile. They have very high-mounted guns and are fun to snipe with using any type of autocannon. A version also exists with many arm-mounted missiles which are great for both SRMs and LRMs. The Hero-version, the Firebrand, trades half the high-mounted gun barrels for energy slots, instead, providing more diversity. These Mechs often work best with fragile, but lightweight XL engines and loads of weapons to serve as "Glass Cannons."
Inner Sphere Hunchbacks are squat little fellows at 50 tons, and offer a good mix of energy, ballistic, and missile options.. But are a little lacking in the missile department. You'll find they do best with a big gun and many Lasers to back it. They have excellent torso-twisting ability and can swing their arms around so far that you can run in a straight line and still shoot someone who's directly behind you.
Edited by Prosperity Park, 04 March 2016 - 01:17 PM.