Hey Sly, I just confirmed that all three of these, Alloy, Nectar and Ozone work perfectly from inside BIAB. Just install them and then, in the mixer, click the plugins tab and then, on the track where you wish to use the izotope tools, click [None]. This will pop up a dialog where you simply choose your plugin (Alloy, Nectar or Ozone). Once you pick it that tools interface will appear and you can select a preset, tweak it, etc. And when you export your tracks these effects will be applied and saved with the tracks.

So, there you go...no external DAW required! And although I did not test with RealBand I'm sure it will work there too. This BIAB/RealBand is an amazing piece of software!!