need to create powerful/surviving class for high-risk e6 3.5

[Gnar]

so I'm in an e6 group, all core books, except pretty much all 3.5 feats are allowed.
I made a wizard and was optimizing the hell out of him, (didn't cast a single evocation, lol) and then we got slaughtered on an expedition, so now I'm looking to make something just as powerful, but with a lot more survivability.

It's mainly the first levels that I'm worried about, so please don't just focus on epic level. The game is pretty much episodel/open sandbox, but super risky (there's a whole thread dedicated to the player graveyard)

I'm thinking a cleric, but I've never played cleric before. All I know are the people in my group who make melee fighting/healing based builds (which I've heard is the worst thing optimization-wise)
what are your suggestions?

[Srasy]

Be a Druid you can fly and burrow or fight your way out of most fights... you can have a beast of an animal companion also I would advise taking natural bond and go into beast master for lvl 6 then start taking feats that give yourself extra party members aka wild cohort leadership and dragon steed...
also try to get greenbound and/or ashbound summoning and/or augmented summoning... and obviously naturel spell...

This character I think would be very survivable with its good fort and will saves d8 hit die, lots of summoning and healing spells, the ability to fight and melee and ranged effectively (Fleshraker FTW), and control the battlefield and buff allies...
Druid is one of the best classes and in my opinion is the strongest class at lvl 6