Just got my first bow, martin saber.. Set to 65lbs. I am shooting 400g carbin fibers..

I have NOT yet purchased any broadheads and I am overtaken by the amount of styles/types..

I have heard that fixed dont shoot well with highspeed bows.. I have heard mechanical dont always expand...

So here is my question for hunting whitetale deer...

If fixed - What and why? I assume you want the same weight as field tip?
Same for mechanical......