I have heard www.americanmodz.com is good. They sell the old ps2 with a crystal chip pre installed. The HDD needs a network adaptor but that is not hard. Maxtor is what I use and it seems to like it the best. You connect the HDD to network adaptor and slide it in and tighten the NA and thats it. I hope this helps.
For the HDD you can get it at www.newegg.com or any place you get your HDD's. The Network Adaptor if it doesnt come with it can be boughten at any gamestore or www.newegg.com/.
One more edit: The buying a Network Adaptor is if you dont have a Online Bundle. The hacked Crystal firmware will allow you to play backups.