Buying an IPhone 4S with Straighttalk?

So I've finally earned enough money and decided to buy an IPhone 4S with straighttalk and the 45$ unlimited plan. I was looking at reviews and now I'm confused on whether I also need to buy a micro SIM card and/or an activation kit. What all do I need to buy to activate and use the iPhone 4S with straighttalk?

My suggestion would be *not* to buy the iPhone through SmartTalk. Often the phone you get from the no contract providers are locked to these providers. What you want to get is an unlocked iPhone and buy the micro sim. You can get it for only 99 cents on Amazon or eBay (or pay full price through the site to make it easy). This is they Bring Your Own Phone program, which requires an unlimited plan, but that's what you want anyway.
The perks of buying an unlocked iPhone vs buying the Smart Talk branded iPhone is that you can always take your unlocked iPhone elsewhere. Smart Talk phones can only be used with Smart Talk though. Let's say later you wanted to switch to Net10 or Aio or another service that's cheaper, you're going to be out of luck. Check with Smart Talk customer service to make sure this is correct, but I'm pretty sure that's true.
If you buy the iPhone on Smart Talk you will not need a micro SIM card. It's listed under their FAQ:
"7. Does my iPhone use a SIM card?
No. Although your iPhone on Straight Talk may contain a SIM slot, DO NOT insert a SIM card into it. Your iPhone on Straight Talk works on a CDMA network; inserting a SIM card could alter your settings and stop it from working properly."