Most newer designs of boards are 3.3V. The days of 5V are coming to a close.
Why must it be 5V? Is there some 5V only device you need it to be interacted to? Could you use signal level shifters?
Why must it have 40 digital pins? Could you not use I/o extender chips?
I suspect the reasons you think you need these things can probably be overcome in other, possibly better, ways.