What were the names of the members of the team who first started the BAU?

Yeah, besides Rossi, Gideon and Hotch has been mentioned Max Ryan, who appears in episode 1x15 "Unfinished Business" and is mentioned as Gideon's mentor in 1x19 "Machismo" Katie Cole has also been referred as a former BAU agent in 2x02 "P911"

I hope this helps you :D

Gideon,Hotch,Reid,Elle,Morgan,JJ,Garcia

Spencer Reid, Aaron Hotchner, Elle Greenaway, Penelope Garcia, Derek Morgan, Jason Gideon. Jennifer Jareau doesn't come in until the second episode. And David Rossi doesn't come in either until third season and Emily Prentiss comes in at the second season.

Gideon, Elle, Morgon, hotch, Reid, and Garcia JJ came in season 2