Are there non-flickering types that will not be noticeable on start up?

Yes. You are looking for a type that has a high frequency electronic
ballast.

I'm also a little concerned about the coldness of the light bouncing off a
white ceiling. Can anyone suggest a tube that might be closer to daylight?

Daylight is actually quite cold. You want a much warmer tri-phosphor tube if
you want to match tungsten bulbs.

Christian.