I think you can organise from either. In fact, I think the transfer from VF is probably quicker than from LVI, although a lot depends on the speed of border formalities.
Try asking on the Zim forum, I know I have seen people recommending particular operators.
Hi, that's a good itenerary, starting with Hwange & then chobe day trip. The day trip to chobe is one of the most common activities on the menu in VF done by most of our visitors. This trip offers one of the best game viewing both in chobe & on the way to & back on the Zimbabwe because it's wild life area from VF to the border.
So on your way into Zimbabwe make sure you get double entry or kaza visa in case you would like to go to Zambia as well.
My Way Taxis Victoria Falls Zimbabwe.
You can have a look at some of the well respected local activity companies for options - Shockwave Adventures, Wild Horizons, Shearwater. Often they will be selling the same trip but under a different name. The Chobe day trip tends to include one boat safari and one land safari, which is probably a good mix. I found Chobe (at the Kasane end, where the day trips run) to be busier than Hwange and enjoyed my time in Hwange more.
Did the Chobe day safari last week. Great day. We organised from Vic Falls and paid in US dollars and saved a lot of money. We had purchased Kaza visa at VF airport once again you need $US cash. We still had to queue at both borders,
For the cruise we were on a small boat (9 people) unfortunately you couldn't move around and it was incredibly hot (approx 35 degrees) and no shade - I would of chosen a larger boat with more shade.