EXS 24 Logic Sampler Users Group

I am leaning towards OPUS bundle. The extra instruments in Opus 2 are very impressive ! 
BUT , i need advice about method of working with a dual gig G4. I have 1.5 ram.
CAN you work with a section of the orch at a time, bounce to audio and add to it that way , 
a section at a time ?
Does anyone work this way or recommend VSL at all ?

many thanks

Lynne