HC (Heavy Carrier) Mk. 2EL
~75 tons to maximum 400km orbit and return
Used a bit of part clipping and some minor exploits (shock cone intake behind the rapiers to reduce drag and make them look nice)
To fly, take off and climb at 5-10 degrees (depending on payload, steeper is for lighter loads) until about 20km and 1400-1500ms airspeed. Turn on wolfhounds, switch rapier mode, shut off whiplashes, and increase angle to 15-25 degrees (again, payload dependent). Climb on stabilize mode until around 35-40km, shut off rapiers and lock prograde until required orbit alt, then do a burn at apoapsis to circularize.