Logic Level Translator caveats
Sometimes I have found that having a lot of logic level translators is more trouble than it is worth. Is your device 3.3V tolerant (I'm assuming you're going from 2.5V to 3.3V)? Assuming you are using the Arduino Due and taking a quick look at the Atmel SAM3X8E datasheet, it seems that if VDDIO is 3.3V, V_IH can be as low as .7*VDDIO, or 2.31V and still read a 'high'. Therefore, your 2.5V device should have no problem driving an Arduino input. The question is if your device can handle the 3.3V that the Arduino will put out. 

Assuming you don't want to modify the Arduino to simply use 2.5V VDDIO (I bet it might be as simple as changing up a regulator or a resistor), you can actually just use a diode array (for example, a CMEDA-6i, which is a quad diode array that has a convenient forward drop of 1.0V) when going from the Arudino out to the device (you don't need to worry about the other direction). That will limit the voltage the device sees to 2.3V. You can do it even simpler with just resistors (or resistor packs), but you need to look a bit into how much current the inputs on your device actually draw and without knowing what that is, it would be hard to recommend a part.