AXE I/O is nice for guitar. I don’t play the guitar but I work with one that just got the interface and it is a very good device for inputting guitar. He uses a Mac Mini and Amplitube 5. Sounds really good.
You need an expression pedal anyway right? At least a volume pedal! So wouldn’t it be nice if the volume pedal and the audio interface was one? Well, such a beast exists, but sadly it’s been discontinued. Why? Who knows. It makes so much sense, I’m amazed others haven’t come out with their own version. The IK multimedia Stealth Pedal is a highly quality USB audio interface and expression pedal in one. Built like a tank too! I use everyday! Of you can find one, get it!