I'm staying by Coconut Bay. Villas Pappagallo specifically.
I'm looking for a 3 tank dive to the North wall.
It seems that there are 2 docks that Dive Ops have their boats. One in Georgetown and another in West Bay.
Villas Pappagallo is not near Coconut Bay; I've been to the Ristorante Pappagallo (pricey but great Italian food and beautiful tropical birds!) and you will be located as far away from the East End as you could possibly be and still be on land, and you won't be all that close to 7MB and George Town either - although they are closer than the East End.
In fact, you won't be near much of anything, you will be "beyond Hell and gone" and I mean that literally because there is a small, post-office and tourist trap on that end of the Island named "Hell". That entire end of the island is named "West Bay" but it's a large area. If you are under the impression that the North Wall is near the East End, you are mistaken.
The places where dive ops berth their boats varies somewhat with the seasons and the weather and their locations. West Bay Dock is a popular spot but it isn't very close to Villas Pappgallo, either.
IMO it would be better to stay on the west side of the island, in West Bay but closer to the West Bay dock (near Coconut Bay for example) to have easier access to some of the more popular venues and the dive ops and dive the North Wall.
Some ops do occasionally offer a 3-tank dive trip but they are rare and will further limit your options. It is more common to book 2-tanks in the morning and 1-tank in the afternoon after lunch, either a boat or shore dive.
You seem to be studying information about dive sites and trying to pick your favorites sites in advance and then hit them all in a short period of time. That's okay in theory, and the dive boat captain will consider your requests; but then he/she will pick the best locations based on the weather conditions, current, distance, the preferences of other guests, other boats on the sites, etc.
You have a short trip planned and I think that you are going to be spending most of your time driving around the island on the left side of the road trying to get to distant places. Luckily there are good roads on GC, but the roundabouts and signage can be confusing and the traffic can be very bad in popular areas.