I don't understand... D:
All these samples files I listen at... how to know if they will let me choose to play the notes I want the way I want or be fucking crappy loops I don't want (me dun want any loop >:O)?

You can't become a composer without selling your body or donning an eyepatch and peg leg. Best to have a good undead Parrot, too, because actually finding stuff to pirate in terms of soundfonts is extremely difficult.

Well, I've already found pretty huge packs of sounds; only problem is that I don't want to download 6Gb worth of sound files without being sure this is what I want and if it'll work on FL Studio 9.

Last I heard of FL studio (in 2002) it was exclusively for mixing loops onto of other loops and I didn't really care for that prospect. Is it any better now?

Now it has something called "Piano Roll" which basically lets you compose pretty much anything: you choose the notes and how low they last, and you can put effect on every note individually, and select the proper instrument for the notes.

Can it load .gig files?

And can you write parts using actual music notation? I've been using Finale Notepad 2008, and I'm not a fan of the quality of the exported midis.

Nope, not as I know yet.

It really goes back to what IskatuMesk said. I use Sibelius and am quite satisfied with it (Sibelius uses Garritan Personal Orchestra for playback), but it isn't cheap if purchased at retail.

The exact opposite of what someone just said about Finale. Sad day. I was hoping the quality improved.