Ideas for a build in solo arena / fighter-pit setting?

[Kraftword]

Me and my friends are putting together a mini-campaign where we are supposed to survive waves of enemies of different kinds and see how far we can go.

We are going to fight solo or maybe two and two, starting off at level 3 and 4 000 gold. We are going to advance in level and gold every third level or so.

We are going to face many kind of monsters, among them three giant centipedes, six goblins and a choker. This is going to take place in large arena of forests, cliffs, an open field and one lake.

We are going to use point-buy, 15 points.

We are allowed to use all core supplements but preferably not third-party content.

Any ideas of what a good build could be in such a setting? Any other strategies you think could be applied in the arena, fighting styles, using high grounds, bottlenecks and water to your advantage?

Thank you for your time

[lemeres]

Reach is always nice. Getting in an attack before the enemy can get to you can finish them at early levels, and certainly softens them up later on.

The very basics of a reach build would be power attack and combat reflexes. Advanced feats would be lunge and pushing assault (both help to place enemies in a sweet spot 15' away- just the right place to force anything that wants to attack you into an AoO, as well as stop them from getting a full attack, if applicable)

[Covert Operator]

Intimidate builds would be one route to go.

If you want to play tactically and have a large degree of control over what happens, rather than relying on hitting or not, you could go stealthy.

You could make a negative channeling-focus cleric for fighting hordes, and hit things with weapons when not fighting hordes. The ability to use CLW wands is awesome.

Slumber witch would be cool too, but you'll need something else against the vermin (who are immune to mind-affecting)