Sorry; I'm back for now, though I can't tell how long it'll last.
In a more or less random order:
Staves
In Normal Greece, Glowing Rod can turn you into an engine of destruction. +2 to Volcanic Orb when you likely only have one point in it is absolutely phenomenal and you'll see yourself one-shot entire groups with some good timing.
Pharaoh's Standard is what you want, early on. It might very well last into epic and even legendary if you don't get lucky with other drops. That thing can drop as early as Normal Egypt and it's absolutely fantastic. Recharge reduction, energy cost reduction, fire damage bonus, burn damage bonus, and a few minor things, but what else do you need? It's everything an Earth caster needs rolled into a very stylish package. If you have one, don't hesitate to give it a try!
Blastos Fotia: I've never had it drop, hard as I tried. It looks amazing until you get the late-game legendary staves. Huge fire and burn damage bonuses, bonuses to some skills, and even a casting speed bonus. The attack speed bonus seems largely wasted, however.
Eye of Osiris: I'm not entirely sure about endgame staves, really, but Eye of Osiris seems a really good candidate. Pretty good bonus to fire and burn damage, and +2 to all Earth skills means you're half-covered in your more important mastery already. The fire resistance is likely going to be redundant, but poison resistance is nice. Reduction to requirements and the other bonuses don't seem very impactful, though. On the other hand, if you're into that kind of thing, you can do a really good Eye-themed pyromancer with Eye of Osiris, Eye of Flame and Eye of Ra, all of which obviously work really well together! It might not be the most effective, but it's fun.
Goldbristle: I don't have one, so can't tell. The elemental damage bonus, recharge reduction and bonus to all skills look pretty neat, and it seems to have some decent resistances.
Heka Staff: While I'd personally probably stick to pure fire staves for thematic reasons, you're unlikely to use staff attacks at this point, and the huge recharge and energy cost reduction drives a hard bargain. No fire or burn damage bonus, though.
Staff of the Cosmos: I'm planning to revisit my Elementalist sometime, and this seems to be my staff of choice. Bonus to elemental damages, energy cost reduction, and an enormous increase in casting speed. This and Archmage's Clasp should have you pretty much covered.
Can't think of more right now.
As for Flame Surge, I agree: It's better, but it's still underwhelming. As a caster, you don't really want to be close enough to enemies for it to work. Still, if you get its recharge to zero (one of the few skills for which it is possible), you'll utterly mow down melee mobs before they'd have a chance to lay a hand on you. Still, almost all Earth casters will have better alternatives; Summoner seems to be the sole exception, and it actually synergizes well with Flame Surge with its superior durability and Briar Ward.
If you want to focus on Earth, and more specifically Volcanic Orb and Eruption, you'll probably want a supporting secondary mastery. I'd probably recommend Nature. You get more summons to distract enemies, Plague and especially Susceptibility to lower both their elemental and physical resistances to further increase the rate at which you murder them, a quasi-energy-cost-reduction in Tranquility of Water (bit ironic, though), and some other neat survivability stuff, though they're really not all that important if you ask me. Your secondary mastery's purpose should be to allow you to incinerate enemies even faster, and I think that most of the other masteries would more serve as distractions, and wouldn't be as effective at supporting your playstyle. But I could be wrong. (That said, Elementalists are still incredibly cool.)
Nerthus Armbands is pretty good, especially if you do go down the Summoner route, but I'm not sure I'd take it over Archmage's Clasp. Still, bonus skills, recharge reduction, and resistances. The casting speed bonus is pretty tiny, unfortunately.