Upgrading HD to avoid 'hangs'...

Hi

I am starting get more frequent processing alerts, and 'hangs' using Logic Pro X on My Mid 2012 MacBookPro using the internal drive only, and I need to reconfigure the drives. After some research it seems sensible (but tell me if I am wrong) to consider a SSd to replace the existing 750GB internal drive to hold OSX and applications and move the existing HD to the replace the the CD slot which I seldom use, and use this HD to store the audio data, loops, instrument software samples etc; and perhaps get a superdrive for the few times I need to use it.

I would like to know ( i) is my strategy workable in the context of using LPX plus NI, Spectrasonics, East West software instruments and (ii) advice on how to size the SSD. Perhaps someone has done exactly this and can provide feedback.

Thanks and regards to all