The remote cable should be the same from an Astro Spectra to an AS+. You'll need the appropriate interconnect board (my terminology may be off though!) and control head backplate though, if you don't already have those. Correct on the W9 head not working (without software manipulation).
No on the MaraTrac cable, unless you changed the radio end connector. They're totally different from what the Spectras (Astros too) use. I'm pretty sure they will work with a Syntor X9000 though.
How many radios can one man own? Don't ask stupid questions.