basically im at the point i'm going to add plant boosts to the party, and before i start doing that i was wondering if i should boost everyone evenly or give much to just 1 warrior type.

The way im thinking, by barbarian is my arena fighter and main damage dealer, so was thinking of just solo building him into a melee monster to handle the arena better and to ensure the party survives any encounter due to his durability. All strength, speed, resists, con, going to him to make him as tough as possible, able to shrug off any spells, stuns, sleeps, or anything else chucked his way. The rest of the party will be normal average with their regular level up boosts and equipment. Any magic etc will go to my bard/cleric of course he doesn't need that.

So what do you think, should i max boost out my barbarian or distribute the stuff through the entire party. I'm thinking just him for survivability/arena or hard parts where you need your party to survive no matter what.

well, boosted all strength and speed, mental and organic to my barbarian. Spread the rest out, worked out fine barbarian was the main damage dealer might as well get him maxed in offensive power to go along with rage.