The SP1 uses a different style upper body, the bolt and detents are the same as an Ions but that's about it. Doesn't really matter though since the Epi kit was pointless and hardly worth the money anyway.
Like i said already the bolt and detents are the same and so are the barrel threads but that's pretty much it for Ion parts. The Vibe/SP1 uses it's own trigger and board style so those are exclusive too. You can get a Blackheart kit though that will give you eyes as well as a new and better board for like $100.