8:07 p.m. on November 15, 2007 (EST)
Hard shells are waterproof shells, which may or may not be breathable depending on the fabric and treatment.
Soft shells are NOT waterproof, though some come quite close while others opt for more breathability. They're stretchier and more abrasion resistant, but if you're going to go out in anything wet you'll need a hard shell. You can read all about soft shells in this gear guide article:
http://www.trailspace.com/gear/guide/soft-shells-101.html
Component 3-in-1 jackets are simply some sort of outer shell that comes with a zip-in fleece or other insulating layer. So you get three jackets in one, so to speak. The North Face and Columbia among other brands have a bunch of these, usually aimed at the general skiing market, as well as for kids.
As for which is warmer, well it depends on what conditions you expect to go out in (rain, snow, dry) and how you'll be exerting yourself and what layers you'll use underneath.
If I were you and would be sitting in the cold fishing, I'd look for a waterproof, breathable hardshell (as Bill mentioned above). It'll keep you dry and block the wind, important factors in staying warm. Then I'd layer underneath with a wool or synthetic baselayer (no cotton) and some insulating mid-layer(s) like a puffy synthetic jacket or vest (depending on the temps) and/or a thick fleece pullover or jacket.
If you find a 3-in-1 jacket you like, it will come with an insulating layer, though you'd need to judge how warm it is and how well it works with the other layers you want to wear. Assuming your layers don't constrict each other, layers give you more options and will keep you comfortable in a wider range of conditions and activity levels.
I don't know how much you're exerting yourself in your construction job, but it's also important not to overheat and sweat in your layers when working hard. Otherwise they won't keep you warm after they've gotten wet. So a lot of it comes down to knowing when to put on and take off layers in anticipation of getting colder and warmer.
For example, when I stop at the summit of a mountain after hoofing it uphill I immediately put on my warmer hat and gloves and puffy jacket before anything else because I know my body is going to start cooling off rapidly (I'm also a very cold person, so I sympathize with you).
And when starting up something that's going to get my blood pumping I always try to remove a layer or so before I need to because I know how quickly I'll warm up and don't want to sweat all over my clothes and get clammy and cold later. This is especially important in winter.
Hope that made some sense.