Most radars are powered by FSUIPC,one that I know works particularly well is in Rick Piper's H.S 748,thought this is Fs2004.
Whether this can be used or made compatible with P3D variants I don't know.
David Maltby,though now distant from the F.s scene,can still be contacted usually via CBFS,that is of course,if you're using DM's superb Tridents.