I don't have anything set up like that but this would be my opinion anyways.
Sounds like your rifle is going to be your "every day" rifle in which you want it to be able to shoot during day or night. In that case I would find a scope that you mount permanently (or just don't take off) and a NV device that you can detach to give the scope night capability that way you don't have to worry about losing zero on the scope. Also you would be able to take the NV device off and using it separately if desired giving you more flexibility.
That said I have not played around with digital NV so I don't know how those work but if you go with the intensifier tube type I would not go below gen 3 Personally or I think you will be disappointed.
Here is good thread on differences between different tube generations.