Hookset: I have a 3.5x10 Leupold on one of my 270's.
I have a 4x12 Leupold on another and my third 270 has a 6.5x20 Leupold variable on it.
I am a firm believer in having PLENTY of scope power available on my 270's.
If you are choosing among scopes you have on hand then I would definitely opt for the 3.5x10 Leupold.
If not I would seek out a Leupold 4x12 with adjustable objective and fine Du-Plex reticle.
What types of game will you be Hunting?
That would help us help you, me thinks.
Hold into the wind
VarmintGuy