Forget about cheapo plugs, my ranger didn't even like the NGK or Bosch plugs, Only autolite or motorcraft, double platinum. I am currently running the autolite double platinums, she loves em! Fords waste spark system eats up plugs. She hated the NGK iridiums.
If you wanna save a few bucks you do the double platinums only on the waste spark side, and regulars on the other.
as for the driveability issue, PJ made some good points...but when I had the issues you describe it was a bad MAF once time, a throttle body/tps the other time. May vary for you though, for I had already gone thru the stuff PJ mentioned...
Good luck and happy wrenching!