My recommendation is if you plan on keeping the truck long enough to change the plugs again consider the Champions. If not use Motorcraft. The Motorcrafts are cheaper and seem to be the best performing in the 5.4 3 valve. I have seen mixed reviews on the Champions some have had great luck with them, others have had to change out some or all due to misfires. The 1 piece design eliminates the breakage issue if you do replace them again though. FWIW I used Motorcraft for my truck.
I installed the Champion 7989 plugs in my '06 FX4 in December 2008. They're still in there and it runs perfect.
I haven't been following this issue much lately, but I think I read something about a redesigned Motorcraft plug that is either welded, or one piece or otherwise made to not separate. If that's true, it would be a lot cheaper way to go than the $12 each I paid for the 7989.