Thorley headers

[Nima]

Hi everybody;
What is your experience/opinion about thorley headers? I even don't know how much they cost but I read something somewhere that they are very good headers. Do you prefer them to hookers? Based on what I read on different threads, looks like to me the hookers fit well in our trucks. The only concern I have with hooker headers is, I've been told that I can only use long tube hooker competion series (I have 70's 350 engine) and I don't like the fact long tube one hanging low under the truck. Also, Hookers competion series, at least on the picture, doesn't look as tough as some other headers. I know this is too subjective opinion though. Anyways, I'll appreciate your inputs. Thanks, Nima.
P.S. Is 14 gauge steel thicker than 16 and 16 thicker than 18 and etc, or vice versa (excuse my spelling if it is wrong!)