I picked up an M-444 a few months ago. Overall I am very happy with it and have shot 1.5" groups at 100 yds with it.
IAI has the following required 7 US-made parts on the M-444 from the factory:
Hammer, Trigger, Sear (HTS - counts as 3 parts)
Pistol Grip
Floorplate
Follower
Muzzlebreak
If you want to use other magazines, you have to swap out 2 of the foreign parts with American equivalents. I replaced the stock with a US-made Penguin and the gas piston with a US-made. Both were purchased from TAPCO. The stock matches perfectly. The piston so far seems ok. You could also swap out the handguards or charging handle.
I would leave the muzzlebreak alone. The one on there is a zero-climb and the recoil on it is not that bad. Besides, you should adjust the gas system anyway to lessen recoil (yet still cycle the action).
Also, your pistol grip is already American so leave that alone unless you want a different style. I like the one it came with since the cleaning kit comes in it.
I love this gun. I hope you enjoy yours too. Check out the FAL-files at www.fnfal.com for more info.
Regards,
SOL