stay ford OEM for coil packs and plugs, dont go aftermarket as many have issues. As far as plugs make sure they are not the ones that are known to break in half.
Many 05+ GT's have had plugs break in half on removal, its just how they are so be CAREFUL. Even if you let Ford do it, and they know about this.... they will still charge you 100-200 PER plug that breaks regardless if its a design flaw on their part or not
Bushings, Poly is fine but Delrin is better in many ways, you get a worse ride though so its a trade off. Go to maximum motorsports and review their product offerings and info. AmericanMucle has discounts for forum members so you can buy their stuff from AM.com's site and save as well.