BARBEERIAN
Prince
Errrrr, why copper?
There are 2 reasons to get iron over copper:
Iron allows you to build more units
Romes UU needs iron(and thats the only source)
I think we have a little more time then everyone thinks to rush rome. He doesnt have any metal in his city, I doubt he has a settler by now, and his production in his main city doesnt look that great. The worst we might see is 2-3 axes. just my opinion.
2-3 axes is death to a sword/axe rush pre-catapults. You can deny the Iron more easily by snagging the copper (and Julius will probably get more worker techs before nabbing Iron so you'll have a lead). Also, that desert hill with a road and Sisiutil's culture on it (the hill 1-N of the copper) will be A) a 'spy on Rome' tile, and B) a '1-move to his city gates' tile. The 'spy on Rome' tile aspect is the most critical part for me though. You can see exactly when he pops his settler and splits his garrison of archers, and declare war precisely when Rome is at it's weakest point defensively. Early precision attacks like that fare much better than later brute force vs. Axes/archers in my opinion.
Also, axes are cheaper than swords so Siz' can slave more of them faster than swords. Ya they aren't as good as swords vs. archers pound for pound but you'll have a few more and they'll be enough to take a flatland capital with 40% culture. Personally I think that getting a rush on his doorstep faster will deny him working/linking the iron (with the archer/warrior I recommend keeping on the iron while building up the axe force).
Not to mention you can work the gold and wheat once the border pops to crank axes out as close as possible to Rome.