First of all, many welcomes! You'll find some great stuff here.
Anywho, regarding your question on bike make and the old double vs. triple issue - you'll get a lot of opinions, and here is mine.
The Lemond looks like a great scoot. IMHO, you should test ride several bikes to get a feel for which brands/models fit you, and just feel the best. Then, pull the trigger and don't look back!
In terms of the triple vs. double issue, I opted for the triple so that I can maintain a higher cadence while climbing. I did this as I'm working on elevating my cadence, and as a byproduct, I think that I'm saving my knees.
I now know that I made the right choice for me. Consider the pros and cons, and make your choice. Remember that it's easier (and less expensive) to convert a triple to a double than the other way around.