Hey.
First - make sure PS 7 runs native under OS X. I can't remember if it does or not. If not, your friend will want to upgrade to CS or CS2, as I can't see the point of buying a G5 and running Photoshop in Classic.
The Colorvision monitor calibrator you reference in that link has gotten good reviews. I think that's a solid choice. If I read your post right, your friend will be using an outside vendor for the final output, right? (As opposed to making the final prints himself.) If that's the case, that vendor should be consulted early in the relationship. If they specialize in fine art output they should be able to provide profiles that would at least be a starting point. I myself wouldn't ask for a color bar from which to make my own profile. There are a great many variables - type of ink and substrate used being the most obvious variables. Your friend should have a consultation with them to narrow down his preferences for paper. The vendor should then be able to supply him with a printer profile, but that will probably need some tweaking.
"Do we ask the 'printer' for a ColorSync profile of his monitor? " - No - you ask for a colorsync profile of his printer, based on the ink set and substrate you plan to print on. His monitor profile is specific to his monitor and won't be of any help. You friend should calibrate his own monitor (with something like the Spyder2), but then either tag or actually convert the file being sent to the vendor with the vendor's output profile. That's an important step: I personally would save a copy of the file(s) being sent to the vendor with the vendor's output profile. Keep a "master" file that isn't specific to that vendor in case... well, in case your friend wants to do something else with it. If you make your art in a wide gamut color space (AdobeRGB for example) ANY printer profile will need to compress the color range into a smaller gamut. Best to establish a master file/vendor-specific file work flow.
"mode (cymk I asume)" - dangerous to assume. Get the output vendor involved at EVERY step. If they do this with artists they should have a customer service rep to meet with, or at least printed guidelines. In any event, your friend probably won't want to *create* the art in CMYK. If necessary, convert to CMYK at the end, because good CMYK conversions are nearly always specific to an output device.
Make sure your friend understands that profiles are powerful but they aren't magic. They will make things "pretty good" pretty consistently. They might get you 90% of the way there 85% of the time, but artists aren't about "pretty close" are they? There will undoubtedly be several proofing rounds before your friend signs off on an edition, and you should make certain to be clear on what the proofs cost. Also make sure your friend understands that it is nearly impossible for output on paper to duplicate the monitor image.
I gather that your friend has an ink jet printer he will want to use as he develops an image. I don't have first hand experience, but I have been told that the profiles for newer printers are quite good these days. Assuming you have a monitor profile, a printer profile for your vendor and a printer profile for your studio printer, ColorSync can theoretically be told to make the studio printer mimic the vendor's printer. This is getting pretty esoteric but I gather it's done all the time so there should be information out there.
Bottom line: get a feel for the vendor you are considering using for output. Do they treat you well? Do you get the sense that they work with (and thus understand and appreciate) the needs and problems of "real", serious artists? If so, that vendor becomes a very valuable consultant, and you and your friend should tap their expertise in every way you can. You are probably going to be paying them a goodly sum of money - you should get more from them than just spatters of colored pigment on paper.