I recommend a microplane over a dedicated zester. 1) it is a multitasker, 2)better then a 5 channel zester, 3)you can use to grind hard spices on.
A veggie peeler, imo, is going to cut too deep if you are not paying attention and you will get the pith. And even then, a peeler is only going to yield a wide strip of hopefully only the outer most layer of fruit, and you still have to cut it down further, or mince it.
A proper zester is a l"semi" imited tool, but worth keeping in the kitchen arsenal, and well preferred over a veggie peeler.