Anyone know Holley Commander 950's? programming?

That $350 price for the software upgrade and a wideband O2 kit sounds suspiciously low. The later lists for ~$850 at Summit, etc., which an amazingly high price.

I have the same Commander 950 TBI kit (paid $600 used, you lucked out), plus a spare ECU ($120 used). Forgot if mine is Pro. Haven't installed yet. One part I don't see in your photo is the cable to connect to a GM 8-pin HEI module. That costs $80 new at Summitt, but is just connectors, so you might make your own. With that, the Commander can control spark timing. See jkirk's post for a photo and TrailBeast sells the HEI setup new.

I understand it works fine with a standard narrow-band O2 sensor, and has a connector for that. I think most new cars still use narrow-band O2. Until very recently, wide-band O2 was a very expensive after-market option, other than a few VW's and such. You can get wideband sensors for ~$45 new or $20 used today, but still need a conditioning box. I have a ~$100 used setup (no display), plus a hobbyist board someone started that I got cheap. If you do install a wideband sensor, make sure you are ready with the conditioning box. Don't ever run it without a box or it can clog up from soot. The conditioning runs a heater that burns soot off. Wideband sensors don't need to be close to the engine and some kits even clamp them up the tail-pipe. However, closer is best for closed-loop control and there are newer sensors that are faster and better for that.