I am trying to implement mod demod for data rate of few kbps . I would like to know is it better/ easier to implement in DSP/FPGA. I am aware of both C and VHDL programming. I think the code flow and build and test time would be faster in DSP? please suggest? Any particular resource for implementation (like a sample code) to get started?
I would suggest you to use the GnuRadio API usualy used for Software Defined Radio (SDR) projects.
As Marcus Müller said in the comments, it is easier to develop this kind of project and test it with a software implementation.
I am also pretty sure that you will find a lot of existing examples to help you with your project.