["I have a MAC Santoku Superior Chef's knife"]
MAC makes a good product -- I have a Superior Series deba and bread knife.
["Having trouble finding a recommendation from the company."]
The care instruction insert that came with my MACs states the following: "To restore it to razor sharpness, simply touch the blade over a MAC Sharpening Rod or a MAC sharpening Stone a few times, at a 10 or 15 degree angle. Remember that MAC finefine-texture knives never need mechanical sharpening or grinding." The first statement is total nonsense. You'll never get a blade razor sharp with a sharpening rod or a few touches on a stone.
["....could use advice on the best/most appropriate sharpening tool."]
Best = stones, assuming you know how to use them. So the issue here is: are you willing to learn? It's not difficult, but don't bother looking for instuctions when purchasing stones.
Alternate answer: best = the tool you're actually willing to use. Ultimately, you have to decide how sharp is sharp enough, and then guide yourself accordingly. The thing is, a MAC uses a type of steel that can hold a really sharp angle, so if you're not going to maintain the type of edge intended, you're basically abandoning the reason you got the knife in the first place.
There are a lot of good sharpening tools available, but many of them are set for edge angles that are not the recommended 10-15 degrees for MACs. The most systematic and current survey of knife sharpening tools (including stones) I've come across was a 12/8/04 article in the L.A. Times.
For copyright reasons, I can't post it here, but it's called, "Sharpeners Prove Their Point," by Pete Thibodeau. You can probably dig it up on their website.
could use advice on the best/most appropriate sharpening tool. It depends on your abilities, I have stones, a chef's choice, steels, and ceramic sticks. The easiest, least expensive I have found are ceramic sticks. I have several that cost $1, comes in a red plastic holder, smaller than a credit card (but thicker). Stones take practice and are probably do the most damage if not used properly. I gave my chef's choice to my father after I started using the ceramic sticks. I was concerned I would grind up my knives.
If you are interested in the different ways to sharpen a knife, try a home improvement fair, state or county fair, or a sportsman fair. These venues seem to always have vendors demonstrating and selling knife sharpening tools.