I don't know much about worship music, so cannot give specific suggestions. All I can say -out of personal experience- is that:

1- the Yamaha Tyros 2 has maybe the best ballads, with a lot of strumming guitars and that -I guess- could work just fine in a worship contest, even if you wrote that you already have REAL guitarists to play with (but you could always mute the guitar tracks of the styles). The Tyros also has specific Soul/Gospel styles, even if they tend to sound a bit repetitive.

2- Like you wrote, Korg instruments (PA 800 or PA2 X Pro) have a more "live" sound, but maybe not as many good ballads to choose from, like Yamaha has;

3- The Roland G-70 has in my opinion the best Slow Rock and Rock & Roll styles, but in the ballad department lags behind Yamaha; the drums, on the other hand, have a more live sound, just like Korg.

So I guess that you should try to listen to all the three brands and decide which one is best for your specific needs.

I cannot speak about Technics since I never owned one; I have owned Ketron instruments and they could indeed work for your needs, but they are difficult to find where you live, so I prefer to give you a practical advice, like: "this is what I would do if I were you".

[This message has been edited by Dreamer (edited 11-12-2008).]