If I build a rear wheel, which will be stronger? (32 laced 3x) Campagnolo 9 speed hub and 180 lbs.

Or can I use a Shimano 9 speed wheel?

If I build a rear wheel, which will be stronger? (32 laced 3x) Campagnolo 9 speed hub and 180 lbs.

Or can I use a Shimano 9 speed wheel?

The Deep V will likely be stronger all other things being equal but there will be a weight penalty. For all-around riding I think the Aerohead is a better choice. You could beef it up a bit by going to 36 spokes without adding too much weight.

By "Shimano 9 speed wheel" do you mean a pre-built wheel or a Shimano hub? Not to start a war, but my feeling is that, in general, a decent, well built, 32 or 36 spoke wheel is going to be stronger and more durable than a low spoke count pre-built wheel

I have a handbuilt shimano 9 speed wheel, I heard the spacing is almost the same and the shifting is OK?

Some bikes will work, some will not. Using the specs, they won't work, but it all depends on tolerences.

I have a handbuilt shimano 9 speed wheel, I heard the spacing is almost the same and the shifting is OK?

if you are not a stickler for some drivetrain noise and sloppier shifting at both ends of the cassette it may be OK for you. You can also use a re-spaced cassette such as those made by Wheels Manufacturing.

Try the Shimano cassette first and see if you can live with it. I am told the SRAM chain works best with this setup but I cannot confirm that