The BMP085 and BMP180 are supposed fully software/firmware compatible, as long as you don't try to use the XCLR pin that is. Without circuit diagram no way to tell.
Also indeed code doesn't even use the library posted above.
The idea seems correct. Use pins to power the sensors one by one (making sure you give them enough time to start up - see data sheet on how to first initialise the sensor, you'll have to do this over and over again).