I have been more mana conservative and it has helped. I have been using planar girds for GH instead of the spell as well as cutting back on displacement which in heroic levels isn't really necessary in most cases, so my SP's are doing better. I do have the belt which I was lucky to pull on my first run through and I will look at the helm which I totally forgot you had.
Another question though, I know the Riddle of Fire from Henshin gives 10 melee power which is a lot, but would the extra cleave attack from the Eldritch Knight tree be more DPS since it gives you a 3rd cleave to keep in your rotation?