I would recommend getting a pad that is as well-insulated as you're willing to carry (higher R value tends to weigh a bit more), and a quilt that is as warm as you think you'll ever need. You are right that it's much easier to vent with a quilt, so a warmer quilt is more versatile. I have an EE quilt as well as a UGQ quilt. I think you get a better bang for buck with UGQ, and both are very high quality. Make sure you get a quilt that's a little wider than you think you need, and a little longer, as well (especially if you sleep on your side).
