I strongly recommend the Drinkwell Pet Fountain.

http://www.petsmart.com/product/inde...ductId=2754468

Cats love the running water, and it encourages them to drink more (which has lots of health benefits). If you buy one, make sure you get the additional water reservoir to maintain the water level when you're away. The fountain is well worth the money whether you plan to leave your cats unattended or not.

As for the feeder, I use the PetSafe 5 meal feeder.

http://www.petsmart.com/product/inde...ductId=2751315

It runs on D cell batteries and rotates to expose a compartment of food at a designated time. We have two of them, one for morning feedings and one for evening. However, I agree with a previous post that an automatic feeder may not be the best thing when dealing with three cats -- I'd be worried someone wouldn't get their share.

Go with the fountain anyway, though. Your cats will thank you!