It is my understanding that the Heller E-2 kit is a brand new tooling and 1/48 if the information I've heard is correct.
As for whats available, that depends completely on your personal finances. Collectaire have both and E-2 and an E-1 in their limited run, multimedia kit range, but I don't know many who can afford them though.
As for the Hobbycraft Tracker mentioned earlier: I do not recomend it. If you can find the old Hasegawa S-2F Tracker, you're getting exactly the same kit but much sharper moldings.
Good luck