Adobe Audition Compatible Interface

Hi there,

I am looking into buying a new audio interface to record vocals over my music. I have previously used pro tools and an MBOX which is now not compatible with newest mac OS. I'm hoping someone can recommend an easy to use interface that can plug into my iMac.

I have looked into the focusrite scarlett 18i8 and apogee duet. I would like to spend less than 400 if possible. Thank you!