What type of scanner are you considering, thermal or traditional night vision? Both of those won't come cheap, so if you have the funds to purchase one of those, then perhaps you might look at a thermal rifle scope that might serve as both scanner and shooting scope, at least for the time being. The new Hogster thermal rifle scope looks to be pretty impressive and the price isn't too bad, especially for the model that is a 1.3x scope.
As to choosing between the Wraith and 4k, that's really a personal thing depending on what you want from the scope. There are pros and cons to both. The Wraith is somewhat cheaper but lacking in some of what I consider to be "good features" that the 4k has, like longer eye relief, long lasting battery, video that has audio etc, plus it has a ballistic calculator that works very well. I saw a new 4k the other day for $539 (3-14x model), so while the 4k is slightly higher priced, it's not that much higher if you shop around. The Wraith is a base 4x, so field of view (to my understanding, I haven't checked specs) is somewhat less according to what someone posted the other day. The Wraith however, appears to have very good resolution for a digital scope. The 4k requires 30mm scope rings whereas the Wraith has it's own mount, not rings.
So, it's difficult to recommend one over the other, especially since I have not personally looked through a Wraith or had field time with it. Kirsch has, however; and should be able to shed more information on that one.
I don't think you will go wrong with either if digital is the way you want to go for now.