Fireball Marauder??

I am open for suggestions. Incinerate maybe awesome too.

I have a Firestorm Marauder myself doing maps. Tried Incinerate but find it more gear dependant so stick with firestorm for now.
I posted my build and my thoughs in this thread:
http://www.pathofexile.com/forum/view-thread/265554

My firestorm/fireball mara can solo lvl70/71 maps pretty well (unless 0 regen, firestorm mana cost too big). If you go fireball, remember to get a 20% quality fireball. It is VERY necessary since it gives 30% chance to ignite at 20%. This will save you a chance to ignite support gem, and combined with Flammability curse, you can bring the chance to ignite up to around 50%.

I can't afford a 20% one, but i got my hands on a +13% one