Having used LabVIEW, VB and C/C++, I can say that the first tool I reach for is _always_ LabVIEW. Nothing else comes close in terms of ease of use, maintainability, and user-friendliness. That said, I don't consider LabVIEW a silver-bullet. If you need your application to to complex 3D rendering, fast database access, or similar highly specialized tasks, you may need to look elsewhere.
Your requirements are fairly strait-foward and all are common things for a LabVIEW program to do. Were I in your position (and I was, once :-) I would get a copy of the demo version of LabVIEW and play with it for a few days. It isn't disabled (much) so you can see the bulk of LabVIEW's capabilities. If you like it, and I'm sure you will, I would reccommend taking a LabVIEW Basics class. They are well worth the time and cost and will have do doing full development work in a matter of days. Hope this helps and please post here if you need anything further. - Jim Cavera
