Hi Kyle!
There are only a couple of shots of the new helmet and someone spotted with white boots on, so really not enough material in my humble opinion to build an ep7 TK yet. I believe there are some threads on whitearmor.net if you want to investigate that more. It's definitely too easy to get "kid in a candy store" with all the various costumes.
Either way, whitearmor.net is where you want to get started for anything stormtrooper related.
As far as ID numbers go, you get to pick from a list of available numbers after you build your costume, get it approved by the GML, and then apply with the 501st.
http://www.501st.com/databank/Membership:JoinUs Joining can be a long process with a lot of waiting, as parts can be hard to find depending on what you're doing and how crafty you are. My own build was 5-6 months. While you are waiting and working, there are usually spotter opportunities posted on the forums here. It's a great way to get your feet wet, check things out and stop stormtroopers from stepping on small children.
