General Cycling Discussion - Which bike? And some questions

Hello. I'm looking at getting into biking. I love the sport. Got a 700c denali from wal mart, started riding it, and love the sport. So much, that I want to get away from the car completely. The problem is, that bike is way too tiny for me. I believe its a 50 cm, but I'm 6 1, so I need something a bit bigger. My neighbor works on bikes, all day long, left and right, and I've learned a bit from him. I know I want a light bike, I know I want good parts, and I know I don't want to have to get another bike again. There are three bikes I've found on craigslist, and I don't know enough to make an informed decision, so I'm hoping you guys could help. I'd ask my neighbor, but he just keeps trying to sell me his bikes, and they are all over $1000.

The three I found are:

http://stlouis.craigslist.org/bik/1226951505.html

http://stlouis.craigslist.org/bik/1257242637.html

http://stlouis.craigslist.org/bik/1257036212.html

I like the idea of the steel and carbon frame on the lemond. From what I've read and been told, it offers pretty much the most comfortable ride, which is very important to me.

Are the bikes "worth" the price they are asking?

The lemond is from 2002, but it has Dura Ace components. What does that compare to, in terms of quality to something a bit more recent? I've seen it, everything on it, except maybe the chain and the front derailer should be Dura Ace. It has some scratches on a shifter, and the paint is rubbed on the top tube. The others, I haven't seen yet.

What should I look for when looking at the bikes, to see if I like them? I'm obviously not going to be able to take them on a 20 mile commute before buying, so I don't know.

Have the sellers meet you with the bikes at a neighborhood bike shop that is convenient for you. The techs at the bike shop can verify the condition of the bikes, and that they are your correct size. In return, pay the bike shop tech to "tune up" the bike for you, and buy a good set of front and rear lights so you can ride safely in the cool of the evening.

Fit!

If fit is what is wrong with your bike now, you shouldn't even be considering those bikes without first confirming that they are your size. At this point, don't get caught up in "which bike is the best." If you can't tell by looking at them, chances are you're not going to be able to feel a whole lot of difference either, given your inexperience. (no offense!)
Rather, look for a bike that fits you like a glove and if it isnt a total piece of crap (which you should double check with the forums on), i bet youll love it.

Have the sellers meet you with the bikes at a neighborhood bike shop that is convenient for you. The techs at the bike shop can verify the condition of the bikes, and that they are your correct size. In return, pay the bike shop tech to "tune up" the bike for you, and buy a good set of front and rear lights so you can ride safely in the cool of the evening.

Very good advice there. The fit is very important.

The Lemond only has the 8 sp cassette, but would be worth offering $500. The Motobecane is a name that has no snob appeal but is an excellent bike with up to date components.

There is nowhere really centrally located for all three of those bikes. I'm assuming you mean to take them there separately, correct? It wouldn't be very fair to the other shops that don't appraise the winning bike if I did it that way, would it?

They should all fit me. I'm about 6 1, and I was told I needed a bike about 58-60 cm. That's what I've been looking for. I'm really hard to be found "uncomfortable". I mean, I'm on a 50 cm bike now, and I wouldn't call it uncomfortable at all. I'm just worried that my knees won't love me if I stay on it too much longer. But, even with that said, I'd like it to feel comfortable to be on :)

Edit: about how much would it cost to upgrade to a 10 speed cassette? Would i need a new derailer, shifter, and cassette, or just a cassette?

The Blue Denali is a 57cm bike. I am 6'2" and had a Denali bike. And well soon have the newer version of the Denali. I have a 35" inseam so I had to have 31.25" distance from cranks to the top of the seat. The seatpost the comes stock on the Denali is long enough to allow for the distance. But I did have to move the seat back to its back most position. To obtain a comfortable reach to the break hoods. I think that if you try repositioning the seat and handlebars you will find the right fit.