Powerhead question

[gregzz4]

You're going to get lots of varying answers from users with different tanks and experiences.
There's no hard and fast rule to answer your question with. You could use X powerheads with Y corals, and then have to either move or replace them when you change Y to Z. Plus, if you have a sump, the outlet(s) can come into play as well.
You would do well researching your corals to find out what they require before you spend the big bucks.
So basically, read all the replies you get here, but don't take anything verbatim.

You may get some better responses if you post the dimensions of your tank and what critters you have/want to keep.

Good luck !