info, it's an honest question. But you'll soon find that orchestral libraries play well together. Once you get quality core sounds like VSL, you can sneak a lot under the radar from other libraries. As a rule, the music that is moving or repetitive goes to VSL, and the sustains and one-shot sounds may be less conspicuously given to other libraries.
The two initial factors with reverb are: 1. How and where was the sample recorded? and 2. How long is the amp release tail of the ADSR? For example, when I add to VSL some SAM Brass and I use the "far" samples, I pull back on the long hall because the sounds were recorded several feet away. I add some small hall to round SAM out. VSL gets both halls, as their samples are recorded in extremely clean, dry environments. From there, I bus equal amounts of both libraries to more processing to homogenize the final effect.