Need information about adding inverter to 2001 Doral 250 SE with AC

[speakermakers]

So I have a 2001 Doral 250 SE with A/C and want to add an inverter and a bank of batteries to run My A/C at night. I am wondering if this is reasonable. I am willing to upgrade my alternator/bateries as well as charge with shore power the following day. My question is how many amps does the A/C draw? And how long can a bank of two large batteries power the A/C?
Also wondering if anyone has or can tell me where to get access to electrical diagrams for my boat. after looking behind the electrical panel it appears that some prewiring for an optional inverter is already there. I would like to find out what is required to finish the job.