[Iron Heroes] Using the core spellcasters...

[Irda Ranger]

What mearls has to say

FWIW, on Monte's boards Mike Mearls mentioned that either the Warlock or AE's Magister, sans equipment, would be fairly balanced with IH characters.

 

[Kaos]

All buffing spells have to be carefuly checked and possible weakened or removed.
Cat´s Grace could give only a +2 bonus to Dex and last only 1 round per level.
Spells like Magic Weapon and Greater Magic Weapon would be unbalanced against humanoid opponents (since armor DR is DR/magic) and should probably be removed.

The IH Arcanist can cast the equivelant of a Cat's Grace (or any of the other "+4 to a stat" effects) at first level if his primary school is transmutation, and have it last for up to 2 minutes. At level 5, he can double the bonus (+8 to any one stat.)
He can also essentially cast Magic Weapon starting at 1st level (up to a +2 enhancement bonus,) and have it last for up to two minutes as well. At level 7, he can up it to a +5, and at level 17 he can do up to a +10 enhancement bonus. It's assumed that this grants the ability to bypass dr/magic, but since it's not explicitly stated that might not be the case.

He has to make a channelling check to pull these effects off, but the first stage ones aren't too hard (DC 9, with a +2 bonus.)

So if you run standard IH, you've already got access to those effects. But there are those who think the IH magic system doesn't quite do what it should do, and does a few things it shouldn't...