I am about the same stage as yourself, and have looked into all area's of the theory study. I have been using the Aviation Theory Centre &Trevor Tom books for my CPL theory, along with Bob Tait's VFR Day study guide for the PPL. Home study is ok if you can be dedicated to it, however, I find the ground school is great because you have to do the work, plus have someone to help you if you dont understand something.
I am considering when I get to PPL that I might do all of the CPL theory at ground school full time, and get it all out of the way. Not sure if this is a good or bad way to do it.