Welcome to MINI2
I suggest you go for the S. A lot of people end up upgrading to an S or wanting an S after a while anyway. The extra power is always enjoyable, but also convenient. The S revs lower at cruising speeds, which is a pleasure as well.
When it comes to colour, the best thing you can do is go for the one you want. Even though some colours are more popular than others, you'll quite possibly see other MINIs with your colour no matter what you go for (unless they personalize it further, aftermarket). Go with the one that you like the most, because part of the reward is looking at the car and feeling good about it.
Take your time if you can. Make sure that you go for what you wanted. I understand the feeling. I took a long time to decide what colour I wanted, and what options I was going to go for. Fortunately, I can say that I am completely happy with my decision.