I would go for the Delta, nearly bought one myself, I have a redbay 6.1 now that we love, our second boat, we bought a Humber Assault (first boat) from new, bare boat which I fitted a Tohatsu 70C, great little boat but hull is only really suitable for in shore cruising with no big waves. loved the boat, great starter boat.
If I knew then what I know now I would have saved some extra money and bought a Humber Destroyer/ Attaque, the hull is much better and easier on the passengers.
If you get the chance try and go for a deeper v than the Humber Assault.
And I agree keep the Delta or your deep v rib simple with a single sensible powered engine