Its hard to tell if the frame needs it or not without actually seeing it. I have not seen a factory direct frameset from IRO before, so I dont know what they do to the frame pre ship. Either way, I dont think doing this yourself is that good of an idea, mainly from a financial standpoint. The BB and HT tools for this are ridiculously expensive for someone that might be doing this once a year. The headtube reamer and facer (Park HTR-1B) and the BB chaser and facer (Park BTS-1) will each run you in the neighborhood of $500. EACH.

These are shop tools, not consumer tools. They are expensive and worth it, but only to a shop that will use them regularly and will make their money back from them. Go ahead and support one of those shops. They will let you know what needs to be done, do it for you, and make sure its done right.

It would really suck to drop $300 on a frame, another $1000 on tools, and then crossthread your bb. Take it to the guys that know what they are doing and support your local in the process, everyone wins.