I dont use ivms...i prefer
blue iris (its much more advanced but requires a more powerful pc)...you can certainly record to sd card and to the pc simultaneously and use the sd card for backup...
The widest angle you will get is about 100 degrees when you run the camera with a
2.8mm lens in 2mp mode (you are actually better off buying the 2mp version because it has better low light vision)..This view will be on par, maybe a bit wider than your logitech...remember that logitech uses diagonal fov in their specs while logitech uses horizontal...eyeballing video of both tells me that hikvision is even wider.
As far as alocating space ivms will allow you to allocate a chunk of diskspace for its use..