Set the bow up & try it out I think you will like it ; Your used stuff is going to work fine

i know, I just figure if im going to have a nice bow I would like nice accessories to optimize performance... getting some nice offers for mine

Ya I want to see you playing with that new bow 

got an offer for a Carbon Matrix with rest and Hogg-it sight...

I got a Bowtech Destroyer 340 last year.  I haven't stuck anything with it yet but man is it smooth and super fast.  $500 should get you something pretty decent 3 or 4 years old.  Or roughly the price range of a new Bowtech Assassin.  The Assassin's are a very highly rated bow at a really good price.