Here's my 2 cents.
If the guitar player already has protools, why not get a mbox 2 mini. Its has a USB interface and comes with protools LE; this will let you record into an existing protools session, and you can also mix/punch in, etc. as well. Its one of the cheapest way to get into protools. You and the guitar player can then just swap session files.
I disagree with the comments about recording to the internal system hard drive. Of course, you can record to the internal drive, but an external will give you more options down the road and will be more stable if things get complex. You will also find that if you do much recording, you will begin to run out of room. I have multiple external firewire drives with a protools LE system; it is rock solid. I can also use them with the USB port. I suggest you and the guitar player consider going in on an external enclosure that has both firewire and USB ports on it. Then you're compatible with anything. Put a large drive in it. Then you can just swap the external with the session files on it with the guitar player as needed.
Also, think about a second external for back ups. . .
If the guitar player already has protools, why not get a mbox 2 mini. Its has a USB interface and comes with protools LE; this will let you record into an existing protools session, and you can also mix/punch in, etc. as well. Its one of the cheapest way to get into protools. You and the guitar player can then just swap session files.
I disagree with the comments about recording to the internal system hard drive. Of course, you can record to the internal drive, but an external will give you more options down the road and will be more stable if things get complex. You will also find that if you do much recording, you will begin to run out of room. I have multiple external firewire drives with a protools LE system; it is rock solid. I can also use them with the USB port. I suggest you and the guitar player consider going in on an external enclosure that has both firewire and USB ports on it. Then you're compatible with anything. Put a large drive in it. Then you can just swap the external with the session files on it with the guitar player as needed.
Also, think about a second external for back ups. . .