As of 3050 the IS only have access to two Quad Mechs. The 
Scorpion and the 
Goliath. Only 3 Clans have Quads. They are 
Thunder Stallion, 
Snow Fox and the 
Fire Scorpion. 2 of these clan would not gain worlds in the IS until after th Clan Invasion was over. The third would not make it into the IS until 3071. More Quad designs start trickling out of the factories starting in the mid 50s.
 
As for 100+ tons mechs I believe there are only 2 deigns ever made.
 
The first was the 150 ton 
Superheavy BattleMechs named the 
Omega was produced in the 3070s. The Factory on Terra was destroyed during 
Operation SCOUR. The bulk of these 'Mechs were deployed in and around the Devils Peak command post used for 
Precentor Martial Cameron St. Jamais' final stand, but some 
Omegas also saw service around Hilton Head and in Cairo. 
"all of the prototypes produced by Skobel are believed to have been destroyed in action."
 
The second was the 135 ton 
Superheavy BattleMechs named the 
Ares unique tripodal chassis was produces in 3132. Non were ever seen and are rumored. The video is a fan made video. The Battletech timeline is not up to this time period. So we will have to wait to see if they are really made. the description on Sarna does say 
"The Ares represents a series of 'Mechs that are built to exceed the 100-ton mark." Does this mean there are other Superheavy BattleMechs? One unique aspect of these 'Mechs is that they are manned with three personnel.