I'd see about getting an S900 again for a few days, and trying those edits out. From what I have heard, there's a larger selection of Praise and Worship styles for Yamaha (and possibly Korg) than any other (you won't easily find them for GW-8, that's for sure!).

The DGX is probably a lost cause, sadly. A very washed out sound, IMO...

If the church can afford it, a T3 might be an excellent choice, with some better drums than the S900, and the possibility of later adding more if Yamaha make an expansion pack for the sampler, or a PA800 might also be something to check out. Lively drums, for sure!