Items on the champ can fall into two categories: Items that help the unit and items that kill enemies.
The Iron Curse Icon is not a bad helping item in a large unit such as the one you have but the items I prefer are the killy items with the Blood Statuette of Spite being a favorite.
That 25 points spent on a potential turn one enemy mage death is brilliant, especially against elves (all types) that are so prevalent in my area.
The other set up I like is to give him the Sword of the Hornet/Sword of Swift Slaying. Nothing like accepting/declaring a challenge from a CC monster lord/hero that charged in and go first or simultaneously then proceed to get a wound or with luck two. I've pulled off some nice underdog victories with my TG champ in this manner.
As for the standard, well the TG unit is quite likely going to be the target of lots of shooting so the -2 to hit at all times (-1 for long range and -1 for the standard or -2 from the standard at close range) is nice, especially if the unit had to move earlier. On the other hand a large unit such as yours requires it to be actually up close and killing things in CC otherwise it is a HUGE points sink so a banner that helps in CC is nice, the War Banner is a good choice, if you face lots of heavily armoured units then the razor standard isn't bad either for a -3 armor save modifier.