Question about thermostats?

As long as the flexwatt strips are the same:
1. Plug thermostat into wall
2. plug in splitter or power strip or anything that allows you to plug in more devices from a single source. Theres tons of different styles.

examples
http://www.amazon.com/Cables-Unlimit.../dp/B000234UFG
http://www.amazon.com/Right-Angle-Wa.../dp/B001K42BJ8
http://www.amazon.com/Master-Electri...ds=power+strip
http://www.amazon.com/Axis-45505-Out...ds=power+strip

it's probably easier to just go into a home improvement store if you don't have one, they should have something you can use.

3. plug in heat tape to that

If you have multiple plugs for your heat tape, you need to make sure that the length and size of heat tape is the same for both connections.Basically, you need to have the same wattage for each connection to the thermostat otherwise you won't have the same temperature on both strips of tape.

If they are the same lengths (thus the same wattages), you plug the thermostat into the wall, then the power bar with your heat tape plugs into the thermostat.