Can you put an additional 200 amp breaker in a standard 30/40 main breaker panel board such as a Seimens or Homeline load center? The total connected load for main and sub will not eceed 200 amps. Does any one make a breaker small enough to fit either of these within the bus configuration?
Thank you

Typically a sub-feed or branch circuit breaker is limited to 100 or 125 amps. To do what you want you'd need a 200A feed-thru panel.