is there a website that has all the episodes in order to watch online?

link

www.animecrunch.com
www.kumby.com
theres heaps just type 'watch Anime online' into google, most of them will have all of one piece's eps up to date

Yes, the website that I use is called:
www.watchop.com/
It has all the Manga chapters, subbed and dubbed episodes and they're all up to date. A new episode comes out every Saturday at 9:00 PM.