Burton Power do the leads for £20, you have to wait a while but they are good. Failing that, got mine same day from Motaquip for £27. The fookin Magnecore ones are only £100 - where the fook you get £200 from.
Plugs are a couple quid each from Ford, you want the slightly later ones with the screw on caps - check them at the service counter as some are shagged, you'll be able to tell straight away.
Check TPS with a multimeter on resistance, clean up all your multiplugs and grease connections, recheck everything again.

Don't discount the lambda sensors, my car was missing on part throttle cruise two weeks ago and one of the lambdas wasn't connected properly.