The Hastings (a Hermes but with tailwheel undercarriage) was only used by the RAF, not commercially. I have seen a couple of photos on the web of one actually at Nairobi so it seems to have been a standard point for them.
The Halton (a civilianised version of the Halifax, of course) was a pretty uneconomic aircraft to operate. BOAC used them only as long as they had to, they were all withdrawn by 1948. They were then all sold to a youthful Freddie Laker, as dealer, who moved them on to operators such as Bond Aviation Services for the duration of the Berlin airlift (1948-9). They appear to have operated latterly almost entirely as freighter only. There were some unmodified Halifaxes also used on the airlift which commercial operators took as a type of last resort.
Operating to East Africa by 1949 were several operators. BOAC initially went back to flying boats, there are 4 Solents per week from Southampton to Nairobi in the 1949 BOAC timetable, in addition to a weekly BOAC DC3 from Aden to Nairobi. Two independents, Airwork (from Blackbushe) and Hunting (from Bovingdon), operated Vickers Vikings on charter-come-scheduled operations to Entebbe/Nairobi, with lots of fuel stops and indeed nightstops (the Viking being a short-range aircraft) a couple of times a week; the main passengers were colonial expat civil servants and their families, and employees of the abortive "Ground Nuts" plantation scheme in East Africa.
South African offered the best service by 1949 to East Africa, 4 times a week DC4s to Nairobi.
Just in case it looks like I am being harsh on the qualities of the Halifax, above, my father was a navigator on the in WW2 and always held them in high regard.