Here's the specs for OmniSynth 2 (a major update from OmniSynth 1, don't bother looking for it):
Quote:

For someone looking for an affordable multi-sampled instrument collection with a full General MIDI set of sounds, OmniSynth 2 delivers that and more! The follow up to Sonic Reality’s OmniSynth 1, this new version features a sound collection that is 4 times the size of the original! With over 1.3 gigabytes of sounds incuding the efficient General MIDI sound set from OmniSynth 1 this newly updated collection is un-matched in value for the money. Complete with a spectrum of beautiful pianos, guitars, basses, strings, pads, leads and more, OmniSynth 2 is a staple piece for any songwriter, composer or producer of any style of music.

Size: 1.32 GB
Number of Sounds: 246 Sample based sounds (parent)
255 Preset sounds (child)

IK Multimedia has it on the Xpansion Tank page of their site. Current price is $29.95.

Bob, LynB, I honestly haven't done enough with ST2 to tell how well it's going to work with BIAB. I know that it's pretty straightforward in both Acid Pro and Reaper -- click on one of the 16 instrument slots, double-click on the instrument in their picker, boom, ya got noise. Not as elegant as Aria, but not too much hassle. I suspect it may end up being a better fit with RealBand.

Best,
Tom Smith
Win10/64 • i7-8700K • 24 GB RAM
BIAB 2024 • Reaper 7 • Izotope MPS
AKG C1000S • IK iRig I/O Pro