Hoytc,

Under options in BiaB, under Ouput Chords you can select the channel to output chord info, also you can select what kind of chords to ouput (triads, or more complecated 4 note chords).
Set your Digitech Vocalist Pro to receive chord info to the same channel number. Then connect your PC via a MIDI cabel to your Digitech Vocalist Pro, anything that will ouput MIDI (like e.g. the MIDISport you mention) will do the job.

Sofar I have not found a way to let BiaB control the vocal presets.
By the way I use the TC Helicon Voice Works, but the principals will be similar.

Good luck!

Tonnie