Guys,
Maybe you all knew about this but I didn't see anything at all about this until this morning! Apparently Special Hobbies has just released a 1/32 version of the X-15A. I came across a couple reports of it from IPMS last week and it sounds very cool! It's available at least here:
http://www.missionmodels.com/product.php?productid=110340&cat=0&page=1
I am picking one up along with the P-39D!
Cheers!
-Ro