“Needing” to get from point “A” to point “B”, in a specific time frame, is a recipe for disaster.
Most boats depart the Cape (Good Hope) for St. Helena & the Cape Verdes in the Southern Summer (November - April), and benefit from the South-East Trades, and Benguela (sp?) Current
The Canary Current
runs South-West from the Canaries
towards the Cape Verdes, and the Equatorial Current runs Westward, making this a more difficult passage
Good luck! I fear you may need it.