I know this is going to sound offensive, but did you add dechlorinater to the new water? Also, just for future reference, unless the tank is WAY over due for a partial water change, I've always been told to save as much as the original water, and to keep the substrate wet to "seed" the tank when you move it. Your tank is going to cycle again... What about temperature? Fish are very prone to temp shock.... Just a few things that came to mind. What are your Gourami's doing that makes you think they are not well? Best o' luck!
Just re-read.... I guess the new water was the right temp?!?! lol I've only heard of them hitting the top for air, as your mother thought! Hope someone can bring you some better advice!!!