I've ordered adrafinil through http://www.antiaging-systems.com/ and had good success. They sell modafinil as well, but I didn't like adrafinil so I never bothered.
Also, what didn't you like about adrafinil?
Adrafinil helped my focus but totally destroyed my sense of humor. Nothing seemed funny at all and I missed a bunch of subtle jokes. It was kind of like medically induced Aspergers for me.