Look hear for the "rules" on what you can get with eqch license level
http://www.w5yi.org/page.php?id=283Technician, Tech Plus and General Class operators may only apply for a "Group C or D" (1-by-3 or a 2-by-3) call sign format
As a Extra you can apply for a 2x1 or a 1x2 or any of the other formats.
Here is a site,
http://www.vanityhq.com/ that although it will take you a while to understand how to navigate, it will give you all the details you need to know.
Look down the page in the left hand center column for Date Controler Call signs
These lists show the call signs that are expired or cancelled, and the date marking the beginning of the 2-year wait. These call signs are in the FCC's database, and will be available for application two years + 1 day after the dates shown
Suffix 1x2 2x1 2x2 1x3 2x3
District 1x2 2x1 2x2 1x3 2x3
Click on these catagories and you will see calls in
GREEN are available now
RED not available yet or
Black Green available this month
More to learn, but stumble around these sites and ask questions.
You can apply for that vanity call here
http://wireless.fcc.gov/uls/index.htm?job=home for $15 "if you quallify". If you screw up the application, you "loose" your $15 fee that is until you apply to get it back.