Two scumbags who worked for Billy Blanks better have brushed up on their Tae Bo ... 'cause they're heading to federal prison after stealing more than $1.1 million from the fitness icon. According to the United States Attorney's Office, Blanks hired Rhenee Foster and Demetria Gutierrez to handle…

Legendary Tae Bo badass Billy Blanks claims his former financial managers ripped off more than a million bucks from his bank accounts ... and now he's suing them to get back the cash. Blanks filed the lawsuit today -- in L.A. County Superior Court -- against his ex-money handlers Rhenee Foster and…