Any of those companies are fine. You should be more concerned with the specs of each bike. If you find a bike you like, go home and research the specs for that bike. Also, do some pre-research before you go to the stores. A good place to look at bikes is on E-b-a-y. Simply read the ads! Read the ads of the most expensive bikes, and you will see how the high end bikes come equipped. (the down side to this is that you will want a $8,000 Euro weenie bike
) Then read the ads for the lower priced bikes, e.g., the $3,000 bikes, then look at the $1,000 bikes. Etc.
www.bicycling.com is a great site, but there are at least a dozen other ones.
www.roadbikereview.com is another good one.
Here's my personal take on this given your size:
I would want you to be safe, comfortable, and have fun. So, I would avoid carbon frames, unless you are willing to spend $3,000 or more. (even so, a friend of mine is permanently disabled from a snapped fork on his $5,000 carbon bike) I would suggest steel for comfort and strength. They are HEAVIER however. For you, weight of the bike should be a secondary consideration. I would get a Shimano 105 component set if you get a road bike. Mountain bikes have a wider array of component sets so ask the salesman if the gruppo on your bike is as good as the top bike in his store, and if not, what is the difference. If the salesman can't explain the differences between the gruppos, go to another store. (a gruppo is the front/rear derailleurs, brakes, shifters, crankset, sprockets, and may also include stem, bars, etc., but rarely does)
One thing you will rarely hear mentioned is this: YOU MUST LOVE YOUR BIKE. If you don't absolutely love your bike, you will not ride it as much. Among the guys I ride with, many of them would rather lose their car than their bike. Bike aficianados have a near religious experience with their ride.
I once had a bike that was about $20,000 worth of bike, gruppo, wheels, custom paint, etc. I would take it to races and guys would gather around it and ask questions about it. At Ironman UK the mechanic was tuning it up in front of the castle and about 20 guys were standing there watching and asking me questions. Life is short. Don't dance with ugly girls and don't ride an ugly bike, unless you can't afford it. Maybe some day you will understand....If your bike gets you fit, you just might think of it as your life saver.
Then you'll understand, mate.
Best of luck,
Robert