Best chroma key software??

Hi
For most of the time I produce music videos in FCPX. My NeXT project is going to be recorded on greenscreen. So here i smy question.

What kind of software, plugin or app would you guys recommand?
I am in need of stock fotos and videos, and special effects. But I am not sure where to get it?
I was told that Magic Bullet from Red giant should do the job, but I am not sure, so what do you guys think?

Why 'software'?
Have you tried FCPX' color-key abilities?
Have you followed advice given by Marc&Steve ?
have you seen superb results demoed in this thread
www.fcp.co/forum/4-final-cut-pro-x-fcpx/...makey-battle-results ?

What stock-photos/-videos? Any? Formats? Rights? Prices?

What special-effects? (to be quibble: s/fx or v/fx?)

<silly car analogy ahead> "Need the best car - which sould I buy?" ...