Some people don't like the look of a humbucker in a strat, but I don't mind it. Bridge pickups in strats are a difficult position to balance.
You can try using a more powerful single coil bridge like a Duncan SSL-5, you can install a single coil sized humbucker or a humbucker, but then you have to worry about the Values of the volume and tone pots, unless you have more modern higher power singles in the neck and middle. If you don't install more powerful singles in the neck and middle, there will always be a fairly big volume difference when switching between the bridge and the other 2.