It seems to me that this is a two step situation. First is how does your amp drive the Cerwin Vega speakers you currently have? Likely the 75 watt rating is the high recommendation and your 40 watt amp drives them fine. Are you getting the volume you require without straining your amp?
Once you move into your new home, then you can reconsider what speakers you need based on budget, room size, and volume levels required. As aforementioned by others, the wattage ratings means little, the impedance rating should be known across the frequency range and should not stray below 4ohms therein, and the sensitivity requirement is largely determined by room size and volume requirements.
Once you make the move initiate a new thread indication specific needs for your situation.
Good luck in your search.