Dealing with a power amp that need 20A connection

I just bought a used Audio Research power amp without knowing it needs 20A connection.
When I received the amp, there was no power cable included, and I've found out that the amp has a connection that I've never seen before. I thought it might be for 250 Volt, but later found out that this amp needs a special power cable with C19 type female connector and it has to be 12 AWG and 20A.
So, I ordered a 20A 12AWG power cable and a PS Audio power receptacle that supports 20A male connector type.
After reading a few more articles on 20A power amp, I may also need a 20A circuit breaker. The problem is, the circuit breaker for the audio room is 15A. Does it mean that I need a new breaker with 20A to use the amp?
What a hassle.
The seller did not mention anything about the cable power requirement and I assumed that it was included, but the seller didn't seem to have known anything about this amp. 
So, installing a new circuit breaker is something non tech people can do? If not, how much would I need to spend for professional job?
Would it be just OK to use 15A circuit breaker for the amp as long as I use 20A 12AWG power code and don't turn the volume much high?
Thx advance for your input.