my 2 cents ,
Like prior responders , have used both. Actually when I/u say " use Sql Server " , as a programming language , that really means using dotNet and within that there are a lot of routes
1) vb.net or C# , both languages are much the same , the language is easy in both cases , the hard part is that the language is just a tool to use the dotNet framework which is VAST !!
2) windows app or desktop app . MicroSoft built Silverlight to supposedly deliver web-based cross-platform apps , but it never caught on and internally in MS seems to have been send to death row
3) say u go for desk-top app , then the main routes are
(a)WinForms ( around since version zero of dotNet ) but MS doing nothing new with it, but millions of google answers to any item
(b) WPF , Windows Presentation Foundation , mainly a new graphics driven library , but pitched by MS as future of dev apps , again has not really caught on
4) data binding ; main option is
(a) ORM Object Relational Mapping , several versions, like Linq -to-Sql (also on death row ) Entity Framework , or 3rd party like nHibernate . In essence , wraps the real data-base in classes so that everything looks like an object. has some benefits
(b) ADO.NET datasets , much more direct link to data
so , which to use ???
If u have never used VFP , but have used some other languages like e.g. VB6 , would say , bite the bullet and go dotNet
However , like Mike and Olaf above , I'm a long-time VFP developer and I would always use VFP ( quite happy with SQL back-end) , unless the client absolutley mandated NO VFP
If forced to go the dotNet route , I would take SQl Server data-base, C# , Winforms , ADO.NET , that is a fairly conventionsl stack( actually quite similar to VFP combo) , but tell the client it would cost/take 3 times as long and let him decide if he still has religious hang-ups about VFP .
VFP will still be working away in 10 years time , the issue is , will there be developers still around to support it
Sean M