I had a shower over a bath in my old house and loved it. I could put the plug in and have the kids in the bath while I had a shower, the shower filled the bath. I also agree with Murraycod, have a toilet in the bathroom and keep the existing one, if this is your forever house you'll need more than one toilet as your kids grow up.

For resale value a bath would be better but if you're planning on living in your house for a long time and don't want one, don't put one in. You can always revamp the bathroom if you ever do sell the house in the future.