M4A files are too huge!

Hi Everyone!

I'm finally trying to convert all of my CDs to the best file format and sell my CDs, that is if they're worth anything!!

I opted for iTunes M4A format but in the import type drop-list, Apple Lossless Encoder, gives me the Automatic option only and no sub-options such as 128kbps!

I'm a Windows user and trying to copy the songs to my iPhone. But each song/file ends up recording @900kbps and between 45MB on average!! How can I enforce recording M4As between 128-320kbps only? How come iTunes doesn't have these options?

I guess I have to convert them to MP3 or WMA!

Thanks