I am a competitive swimmer and I was wondering, Speedo or Jammer?

I am a competitive swimmer and I have been wearing a jammer for a while at practices and meets. I recently started wearing a speedo underneath a drag suit at practice and have worn a speedo to some meets. Should I keep wearing the drag suit over a speedo, or take it off and just wear a speedo during practice. And should I wear a Speedo or Jammer for Meets? So in conclusion my question is, do drag suits make you faster and are speedos or jammers better for meets?