Using your restraints of an ultralight hover-monocycle with a 2-ton infantry compartment, and making it as fast as possible:
War Chariot:
Small Support Vehicle
Total Mass: 4999 kg
Rating: F/X-?-?/B
Chassis: Hover (Monocycle, Ultralight), TL F [165kg, 1608.75 C-Bills]
Engine: Fusion Engine, Speed 20/30, TL F [2523 kg, 50460 C-Bills]
Fuel: Hydrogen, infinite km Operational Range, TL F [0 kg, 0 C-Bills]
Seats: 1 Ejection [100 kg, 25000 C-Bills]
Armor: 2 Front, 2 Sides, 2 Aft, BAR 5, TL F [208 kg, 3200 C-Bills]
Cargo: 2000 kg [2000 kg, 0 C-Bills]
Total: 4996 kg, 88290 C-Bills
Cruise Speed: 216.0 km/h
Flank Speed: 324.0 km/h
Notes: Uses monocycle and ultralight modification, 1 crew seat/ejector (100 kg)
Since you didn't specify, I made it a TL F fusion job, because that has the smallest engine multiplier on the table. The ejection seat replaced the pillion seat because adding another MP weights more than 50 kg, and the sled doesn't weigh in at the full 4999 kg because that would leave a kg left over, and a 1-kg glove compartment is just silly.
And no, it's not an omni.
If I make it a VTOL and drop that unicycle mod:
Airlifter:
Small Support Vehicle
Total Mass: 4999 kg
Rating: F/X-?-?/B
Chassis: VTOL (Ultralight), TL F [330kg, 2475 C-Bills]
Engine: Fusion Engine, Speed 21/32, TL F [2225 kg, 44500 C-Bills]
Fuel: Hydrogen, infinite km Operational Range, TL F [0 kg, 0 C-Bills]
Seats: 1 Ejection [100 kg, 25000 C-Bills]
Armor: 2 Front, 2 Sides, 1 Aft, 1 Rotor, BAR 5, TL F [208 kg, 3200 C-Bills]
Cargo: 2136 kg [2136 kg, 0 C-Bills]
Total: 4996 kg, 87702 C-Bills
Cruise Speed: 226.8 km/h
Flank Speed: 345.6 km/h
Notes: Uses ultralight modification, 1 crew seat/ejector (100 kg)
A bit cheaper, a bit faster, and it flies...