Rotormatic, I'm going to guess at this, but the 214ST uses the now obsolete CT7-2A. I stated in another thread that this engine is now out of production. The T700-701C on the other hand is still very much in production, which is the engine LA county is using in their S70s (as Nick said). It must be more difficult to support the obsolete CT7-2A, and this may be the reason GE is so reluctant to support it in the firefighting role. I also think the CT7-2A had a rather low production run, which contributes to this problem I think, but I could be mistaken about that.
What's interesting is that the early S-70Cs also used the CT7-2A. It might be interesting to find out what kind of support GE gives these engines in that airframe.