Billboard Christian Music Charts

Can any one explain to me some words in the following sentences?
1-Christian music sales are growing faster than any other part of the music industry. But christian singer and songwriter Derek Webb isn’t padding those numbers.
Meaning of padding those numbers.
2-Dan Router is a Third Coast Artist agent.
Meaning of Third Coast Artist agent.
3-Praise and worship. That’s the kind of music that sells out arenas and makes Billbaord Top 20.
Meaning of sells out arenas, makes the billboard top 20.
4-Chris Tomlin has been at the number one spot on christian charts for 11 weeks runninng.
Meaning of spot on christian charts, for 11 weeks running.
5-On the other end of the spectrum is Derek Webb. Inside his East Nashville home studio, he strums a Gibson acoustic he’s picked up off a long rack of guitars.
Meaning of Gibson acoustic, picked up off a long rack of guitars.
Thanks.
Padding those numbers- reporting false results obtained through sales and surveys- in the recording (or book, or movie) industries, most products are ranked by items sold- and sometimes companies or individuals will provide false information that makes it look like they have higher sales than they really have.
Third Coast agent- from the south east US- centered around the Houston Texas area
Sells out arenas- enough people buy tickets to fill up large cencert halls
makes BIllboard top 20- sells enough of their music to make the list of top sellers in Billboard magazine- this rating also reflects the amount of play the music receives on the radio
Spot on Christian charts for 11 weeks running- this is the list of most popular Christian songs and his songs or album has been the most popular for a total of 11 weeks in a row
Gibson acoustic- a regular wooden guitar- not electric
Top 10 Songs – February 2010