Dedicated line help

Can someone please clarify what I am looking for. I want to setup a dedicated curcuit for my system. I have talked to some electricians about how to do this but am having trouble. My home has the typical electrical meter from the electrical company which feeds into a main curcuit breaker. The electricians seem to push the conversation that my only option is to add an additional curcuit to my existing curcuit breaker and run a line to the outlet. I have read people who have put another curcuit breaker in just after the electrical meter and run it directly to the outlet. Is there a problem with how I am communicating the issue or are they correct?? My main curcuit breaker can take another switch but from other people's posts is the feed directly after the electrical box and before the curcuit breaker better? Does it matter what type of outlets, cable, etc. are used??

Any help appreciated.

John