Fran and Russ are absolutely on the money on this one. If you're a solid two-handed pianist with good left-hand comping chops, controlling the drum fills and variations should be a snap. Leave out the arranger backing altogether. Not only will it be more confusing for the bassist, but it'll have you going back and forth between two playing styles. And, as Russ says, it'll be WAY more realistic (and artistically satisfying). Good luck. Try to get in as much rehearsal time as possible before the gig. If you've ever played in a 'standard' piano/bass/drum trio before, it should be a piece of cake. Also, try substituting a nice tasteful 'Rhodes' on some of the slow tunes. That will provide a little variation. Also, if you're comfortable with it, try a split with piano or Rhodes comps and some easy to emulate lead voices in the right hand. Just suggestions but I've done this many times (with a synth) and it worked out well.

chas