I just recently re-listened to the mp3
at White Labs WLP001
page because I was concerned about fermenting too low as well. The optimal range is 68-73°F, but he talks about folks using it down even in the high 50s to achieve different flavor profiles.
I've got my first batch of graff
going right now, and my fermentation freezer has been below 65 the entire time. I just checked it at day 3, and it's bubbling every second still at 61F. I did use a pretty active starter.
As for whether you need a starter, check out Mr. Malty
for reference. I say make one if you have the time etc.