eventually sonography but right now cna or cma? help

I am starting classes for one of the 2 in 2 weeks June 24th. And I have no clue which would be better. I really want to do some work with ultrasounds but don't know which would be better to help cna or McMahon. Cma is alot more and don't want to do that if its not going to be a much bigger helpful step for me.I've even thought about the phlebotomy class but I don't know what to do..... please help me!! Anyone