No need for pumps at all.  Just attach an open reservoir tank (that you can refill for each rehearsal/performance) big enough to provide the amount of water you'll need and a bunch extra for the hose to your faucet to the back side of the wall where your sink is located.  It is VERY important to mount it as high up on the wall as possible because gravity will be your pump.  Simply run a hose directly to your faucet and when the valve is opened (the faucet is turned on) the water will flow freely from the reservoir.  Be sure to "bleed the line" (turn on the faucet for just a short time) after each filling (or at least initially) to insure there is no air trapped in the hose and you get water immediately when turning the tap on.  Don't forget to include a collection tank (or bucket) to catch the water that may get past the glass or pitcher you intend to fill, and to minimize the noise of water splashing into that bucket, make the hose from the drain go all the way to the bottom of the "catch tank."

To add my 2 zacks worth to that posted by Spectrum. For sets requiring a lot of water in the kitchen. I have used a tiolet cisten fush tank, with the ball cock conneted to a hose. Mounted in the manner of a gravity feed tank, as decribbed in the post. Drainage is just as simple, except have the catchment off syage, rather than just a bucket in the cupboard under the sink, which can create messy overflow & smelly problems, if you can't empty it during the show!