2 piece or 3 shower with surrond

Need to replace the tub/shower unit. It is tiled with and old tub. Maybe not yet but would like to get it figured out first. It is the kids bath/shower upstairs.

I was initially thinking about a tub with a hopefullly one piece on top. Should I buy those together or do you have to? I have seen the units at HD but didn't look really close. Will next time. I could also tile the top I guess. Adv or disadvatages to the one piece? I am a bit concerned on getting the wall unit up the stairs and into the bath. Probably would fit.

Advice/recommendations?

Often, a one-piece tub with surround is put in place before all the walls are up...it would be rare to be able to get one upstairs which is why they make them in more pieces for retrofit. The key to a good install is to ensure the walls are square and plumb, and you level it well on the floor. Tiling is an option, and then, you would want a tub with a factory installed tiling flange. Making things all nice and waterproof isn't all that hard, but there are lots of ways to mess up, so you need a good plan and good workmanship once you select a method you feel comfortable with.

Thanks for the thoughts. How about a two piece, -tub and the wall surround, are they fine?

The fewer the pieces, the fewer joints that could leak. The parts are big, though, so it depends on your stairways, hallways, door openings, and the actual unit you select. I haven't dealt with enough to make a specific recommendation...wait for one of the pros...

Most times these get delivered before all the framing is wrapped up.

Last two I saw came in through a window via a crane.

JW