Class Advice for Iron Gods Campagin

[Icy Turbo]

So I am having some issues figuring out what class would fit well in the composition that we have right now. The group is an Alchemist, Sorcerer, Cleric, Rogue and Paladin who is specializing in Holy Gun archetype. The other characters are more traditional, but what would be a good class to pad things out? There isn't much front-line so I was thinking fighter, but I was trying to see if there were other options that I may not have thought of at this time that could be gained from this thread.

This campaign uses Hero Points, with a point buy of 20 points (High Fantasy), As well as one trait that must be from the Iron Gods, and also a bonus feat. Starting gold is normal for the class rolled, all starting level 1.

[Jaunt]

You've got a skill monkey, some sort of arcane caster, a divine caster, a ranged killer and an alchemist.

Any further info about what your alchemist and sorc will be like?

Just off the top of my head, I'd say Fighter's okay, Barbarian would be great, a Bard would work well if your alchemist is more natural attacks and less bombs.

[boring7]

Need a tank. In between the Alchemist and the Rogue SOMEONE should be capable of dealing damage, but your paladin is going ranged and you need someone to stand there and be a blocker for the ranged guys to hide behind. Fighter can do that, but the wheels fall off that class pretty early (so plan a build that jumps to another class). Barbarian will want an archetype (invulnerable rager, armored hulk, whatever). Synthesist Summoner can do it but has numerous issues with people not liking the class and the reasons they don't like the class.

Key things that a knowledge: local check should be able to tell you; There be robots, robots have hardness rather than DR (so energy damage will not save you, but power attack might), there are places where you really want to have a Face (charisma-skill guy), and learn the technology rules (including the fact that technology tends to be more expensive and less effective than similar magic) because there is technology.