I'm a developer with more than 30 years of experience working with Delphi (yes, since it was Turbo Pascal), and also other programming languages (C++, C#, C, VB, VB.NET, Fortran, etc.). I also have experience developing web services. The conversion from Delphi 2007 to Delphi XE6 depends greatly of the components that were used in the original code (some third party components that were available in Delphi 2007 may not be so for Delphi XE6). If your code only used standard components, the conversion can be done in a very short time. I would like to discuss with you the details regarding this conversion, as well as the rest of the project in order to provide a more realistic estimate of the costs and time.
Kind regards,
Marco García