I would ride with the stock speakers for a while before I went through it upgrading them. The amp can really make or break sound from any speaker.

Personally, I would take oem speakers over mid grade aftermarket any day. oem speakers are designed to last for decades while producing reasonably accurate sound. Most aftermarket speakers cut cost on materials or sacrifice sound quality by using heavier materials(*cough*polypropylene and butyl rubber*) that bend response.