As long as you have a 200 amp panel or gas available.
Where you live, and incoming water temps, and hot water usage, are the important factors when it comes to properly sizing your tankless water heater.
My company site is being built, but in the meantime please go to the site of my freind and supplier, Darrell Thomas. His toll free # is 800-296 7904, url is www.endlesslyhot.com If he can't help you, nobody can.
Please tell him Brian in Lake Charles referred you to him. If you are within driving distance of Lake Charles, LA. (Louisiana) I can help you. 337 430 4649
You are making the right choice, good luck and enjoy.