I know already that when sending music to radio stations use WAV, But what do you suggestion 24 or 16 bit ? thanks.

Welcome to the forum. What you send a radio station is unimportant. What they want is what you will send them. 
 
You want to record 24 bit audio because it will give you low noise and will be far easier to mix and edit than 16 bit. 
 
Once you have a mix and you wish to send it to a radio station you can ask them what they prefer. They may want an MP3 for example.  Your 24 bit session will convert nicely to any format you want. 
 
I hope that answered your question. 

Very true, but I normally send CDR to college radios anyway so the only space being taken would be book shelf space lol

Just send them 44.1 16 bit. CD quality will do. In the end it will end up in a lossy compressed stream of some sorts or get broadcast over FM.

Half the amateur stations don't know about file formats anyway...