I think most anything will do a good job if YOU like the styles...

But I feel that, in a church, there is a little extra you need to do to the styles to make them work in a large environment. You mention the washed out sound of the Yamaha's, and yes, while on the whole I would tend to agree to a degree, I think you would be pleasantly surprised at how better they can sound by removing ALL the reverb (you are already in a large space - why add MORE?) and punching up the drum levels and bass (if needed) and removing any compression from within the arranger if it has one.

You should also take into account any compression that may be being applied to the church's sound system, and see if overly aggressive guitar playing, or singers that 'eat' the mike are ducking down the backing from the arranger. Compress those separately from the arranger...

Lastly is the matter of monitoring... to play well, to FEEL that the arranger IS a drummer, bass player etc., it needs to be as loud onstage as if you had a real one. Allow others to ride on top of the sound, rather than sit within it (as they would if you had real drums) will always change the dynamic, and the whole FEEL of playing music. Care needs to be taken here, or everything will sound 'flat' and uninspiring.

Best of luck with your search...