I'm not new to Apple, I already have a family of Apple products: iPod Touch 2g, iPod Touch 5g, iPad Mini With Retina, and 13" Macbook pro early 2011. Now I'm adding the iPhone. Right now I have a very cheap phone from TracFone I been using for a couple of years and it is time for me to move up. I'm planning on signing up to T-Mobile $80 Unlimited minutes, text, and data w/ 5GB tethering plan(Post-paid). I will be paying for the phone full price from the Apple store. Should I let Apple active the phone(porting my number, and picking a plan), or go to T-Mobile store? Also can T-mobile use the sim card that come with iPhone pre-installed or do I still need to order one?