Doorn.

Q-Regarding Sonar, can he convery to audio and to Mp3?
A-I have not made any MP3 recordings in any form, it is on my list to do list. Sorry no information.

Q-Do I need any additional Harware for the computer to run the Sonar?
A-No, you do not need additional hardware.

Q-What is the best and reliable laptop for this application?
A-I am not the person to ask about a laptop, my knowledge is very limited. There are many on this forum that are better qualified to answer your question.

Have a good day, John C.