I have a project in which I need to monitor 2 barometric sensors. It looks like the SCL and SDA need to be connected to A4 and A5. Is there an arduino that will support two separate devices requiring this type of communication or am I out of luck?
That method of communication is called th I2C bus. It will support up to 128 devices.
Each device needs to have a different address. Most devices have external pins to set part of their address.
The BMP085 pressure sensor has a reset pin. If you hold all but one of the BMP085 sensors in reset you can talk to the un-reset one via the I2C bus. http://www.adafruit.com/datasheets/BST-BMP085-DS000-06.pdf