Personally I like the Eppendorf pipettes; partly because I use them at work and are familiar with them. But another reason is that I can get them inexpensively as used equipment from a local scientific calibration business. Many of the giant biopharmaceutical firms in the area will toss a perfectly good pipette after a certain period of time, which means that the calibration firm has a lot of them for sale for about 1/3rd the price of new.
One relevant question is what your purpose for the pipette is and what volume range you need. If the point is easy measurement of reagents for water tests, then yes, you probably do want to learn how to dissemble and clean these instruments, and how to calibrate them occasionally. If it's just convenient dispensing of suspended coral food, then calibration is unnecessary.
Calibration is going to require an accurate analytical balance. One that will weigh in grams to 2 decimal places is good enough to calibrate a 1000 ul pipette. If you're using the 100 ul or 20 ul versions, you'll need an analytical balance that has resolution down to the tenth of a milligram.
