Always use genuine ignition parts, zetecs have never liked aftermarket plugs/leads in my opinion. Get yourself onto eBay where you can pick up genuine parts etc. I use opie oils for my oils/filters as they only sell quality stuff. Look in the traders section on here and they occasionally put up discount codes.

Cone filters do nothing on an N/A engine apart from make noise and suck in hot air out of the engine bay, the standard air box is best.