I think it would be tough to do all callbacks with one suit. You're flying / taking trains, doing multiple sets of interviews in the same day or series of days. Lots of wear for one suit. If you can keep the suit looking good; avoid soiling it, etc., you should be all right. But unless you can space your callbacks out, which isn't the best option (doing them quickly shows interest / avoids losing your spot to other applicants who beat you to the interview), you probably don't have time to get another suit tailored before your other callbacks. I would buy a couple of white and blue solid shirts and some sober ties. Make sure your clothes are pressed for the interview. Good luck with your callbacks!