If one gets the idea that Antioch wasn't overly fond of Jerusalem, then one should also conclude Antioch felt much the same way about James. By the time of Acts 15, James was essentially head of the church in Jerusalem, and therefore any christian emissaries sent "from Judea" were highly likely to have been sent directly or indirectly "from James". The same word "certain ones" (τινας, τινες, in Gal.2:12 as in Acts 15:1) is merely circumstantial, and doesn't prove my assertion, but the most logical guess is that these were the very same men.
Chronologically, this would mean that Antioch had gone unmolested by Judean controversy until these men came along. Apparently Peter himself was the first one to visit, which seems fairly appropriate, and then while Peter was still there in Antioch, these "certain men" came to visit as well. Again, this makes perfect sense. Acts tells us that Peter encountered resistance after meeting Cornelius. Paul tells us that an "circumcision party" was alive and well in Antioch on the day Paul rebuked Peter, and this "party" must have been the same group, who had just come up from Jerusalem. It seems as if someone in the C party was deliberately following Peter, who very clearly was susceptible to their influence.
So, Paul says "men from James", instead of "men from Judea". Well, Galatians pulls no punches anywhere, does it? But for Luke to say, "men from Judea" may have been just a bare bit of diplomacy. The obvious conclusion to draw here most likely correct.
In fact, the famous Judaizers (who went to Galatia) are most likely also to be identified with these very same men from Judea. At the very least, we know of no other such devouts from the C party who would travel as far as the 300+ miles to Antioch. So, is it easier to suppose that these troublemakers at Antioch went back home from Antioch and then some other group of devout Judaizers left Judea and walked all the way into Pisidia? Or is it easier to suppose that these "certain men" - who had come up from James/Judea, who had already caused such controversies in Antioch - that these were in fact the same "certain men" who went on through the Lion's Gate in Cilicia and found their way to the four very young churches of Southern Galatia.
This view simply makes good logistical sense, and I believe it makes the best sense of the evidence altogether. These men, having just been daunted by Paul in Antioch, must have also heard about Galatia while in Antioch - for Paul had not yet testified about Gentile salvation in Jerusalem (Acts 15:3) - and these men there, in Antioch, evidently decided to move on and hope for better results with new Galatian believers than they'd been able to produce while in Syria.
Finally, this could also explain Paul's literary sequence in building up to the flashback in Gal.2. It seems absolutely certain that these Judaizers had already told Galatia about Paul rebuking Peter... Paul's self defense proves they had tried to destroy Paul's reputation... but the news of the Council (2:1-10) would have been unknown to Galatia because the Council was happening at about the same time as the Judaizers were busily brandishing knives in Derbe, Lystra, Iconium and Pisidian Antioch.
To wrap it all up: Paul's "men from James" were the same men as Luke's "men from Judea". The Council of Acts 15 is absolutely the focus of Gal.2:1-10, and Paul's letter was written to Southern Galatia very soon after the Council had ended. Paul & Barnabas got back to Antioch, parted ways, and then Paul somehow heard that Galatians were in trouble. He sent the letter ahead with Luke - and apparently Titus as well - and those two were probably also keeping Jerusalem's letter in their 'pocket' for back-up. Luke & Titus went on then to find their pre-arranged rendezvous at "Troy", to wait there while Paul & Silas headed for follow up visits in Galatia, having deliberately given the churches some brief time to digest and respond to the letter(s) and letter carrier(s).
That's the simplest way I can see - not to harmonize seemingly divergent texts (blech!), but - to synchronize all the accounts. Or, in other words, that's my brief sketch at a historical reconstruction.
Think upon it...