I use a Bosch Blaze outdoor laser with a view finder. I’ve tried to use indoor lasers without view finders outside and have to say I don’t think they are worth it. You just can’t see the laser well enough without a view finder to make good use of them.
I’ve used Leica Distos for decades, but mine is pretty old and you can get much smaller ones now. On the exterior, I find it helpful to bring a small chunk of white Foamcore and ducktape. I tape it sticking out from an outside corner, and use that as a target with the laser from the apposing corner. Big enough to be an easy target, and white makes the dot easier to see, which is all helpful outside. Of course, I also use Matchphoto which reduces the quantity of measurements I need to make, but that’s another story.