GE H6024NH Nighthawk will be the best performing sealed beam. It's still only 35/65 watt though so they'll be weaker than decent H4's. They will be better than cheap or "pretty" H4's (LMC, eBay, no-name lights).
As posted above, a relay harness will make any light you choose brighter and take the load off of the original wiring and switch. You may have a bad ground or more voltage drop on one side causing the one headlight to be dimmer than the other.
If you do much driving at night, I would suggest a relay harness and GOOD (not chinese!) H4's like Cibie, Bosch, or Hella. You need headlights that will light up farther out than your brakes can stop so you have enough time to react and avoid anything in your lane.
Here are a couple shots of the beam pattern in my daily driver with Cibie H4's, a relay harness, and Hella 80/100 watt H4 bulbs.
Low beam:
High beam:
