I am aware that the commercial voltage for fluorescent lights is 346 volts but am I right that fluorescent lights can be bought for 120 volts and 208 volts?

Wedll you are incorrect about the "commercial" voltage spec. Ballasts are available in all different types of input and output voltages. It varies based on design, usage and bulb arrangement. But bulbs aren't rated in voltage, just size and performance specs.

Canada uses 347/600 volt systems, along with 277/480, and 120/208, and 120/240 volts, and ballasts are available in most of these voltages.

When ordering fixtures, check the datasheet for the voltages available. Some may be special order.

Yes, you will find many fluorescent lights available for 120 Volts in America.