Thx Grumpy_Mike. I have confirmed that the transformer is actually just a power supply (converts AC->DC) and does not contain any driver, so If I select an LED Driver that outputs constant current less than or equal to 650mA (the max current my LEDs take) I should be fine right?
Also regarding the previously mentioned chip (http://www.ti.com/lit/ds/symlink/lm3404.pdf), if the input current (from the power supply) is only 650mA, shouldn't the output current (from the LED driver) also be 650mA? or does the chip regulate the input power insomuch that a constant output current of 1A is always emitted ? (hence the name buck regulator)