I just did another timing belt/water pump job last week. I have found that using a long handle ratchet makes it much easier to turn to set or check timing. Since you are using less force, you are much less likely to over shoot when it gives. Throw in a couple of long extensions and it becomes much more comfortable and easier to keep an eye both marks.
I like this one: http://www.harborfreight.com/12-in-drive-extendable-ratchet-62311.html
I like this one: http://www.harborfreight.com/12-in-drive-extendable-ratchet-62311.html
