Help me buy a bicycle!

Hello, I am Freddy Vega. I am 15 years old and I live in Tulsa, Oklahoma. I have enjoyed riding a bicycle since I was very young. A few years back, I helped raise $10,000 for kids with cancer, through cycling. For the past year I have been biking much more. I have been all around my city on my bicycle. I usually bike 50-100 miles a week. I have been wanting to bike across state and participate in bike tours. My dream is to cycle my way to Chicago, Illinois, where I was born. I have created this listing to raise money for a new bicycle. Right now I have an Ozone500 mountain bicycle that cost $100.  I have easily put three or four thousand miles on it. Some of the gears don't work, the back tire is very bald, and I have to manually press the back brake with my feet, since neither of the brakes work. Nonetheless, I am surprised it has held up to so much use. I wish I could cycle way more, but I don't see it happening with the bike I currently have. I appreciate your donations and time reading this. Thank you and have nice day!

Here is more information on Bike for a Life.  An event i held a few years ago to raise money for kids with cancer. 

http://m.newson6.com/Story.aspx?story=14647033&catId=199427

http://www.tulsapeople.com/Tulsa-People/November-2011/Unsung-heroes/?cparticle=5&siarticle=4

Here are the bike options I wish to get:
http://www.trekbikes.com/us/en/bikes/road/touring/520/520_disc/
http://www.trekbikes.com/us/en/bikes/road/performance_race/1_series/1_1_h2_compact/#