I would think the chip would be cheaper, but I do not know for sure. If the truck is an 01, you probably aren't worried about the warranty. The problem with the chip is, you end up driving with your foot in it, because you can, and defeating the potential increased gas mileage. At least I did
As for the 2 cycle oil, do a google search for "Drews Brew". Lots of people swear by it. I have had 2 Cummins diesels, and with my 2004, I got about 2 mpg better running the mix, and my current truck (2006) does not get any different with it.
RF