Crystan, Reality 2 includes three IBL setups with preview sphere that can be rotated. I pioneered that approach two years ago, when Reality 2.0 was shipped. You can simply analyze the system and extend it to include additional IBL maps of your choice.

Cheers.

Paolo

https://www.preta3d.com
FB: https://www.facebook.com/RealityPlugIn
Tw: @preta3d
G+: https://plus.google.com/106625816153304163119
The Reality Gallery: https://reality-plug-in.deviantart.com