I'd recommend more of a Two-handed weapon Fighter or Barbarian in lieu of using Two-Weapon Fighting.
There are multiple reasons to do so, such as the Accuracy penalties you get from Two-weapon fighting lowering your overall damage, being unable to utilize Power attack fully because of said accuracy penalty, and the fact that your gold is being spent on two weapons instead of just using all of your gold on a single weapon.
Also, Barbarian gets a D12 hit die against a Fighters D10, gets a full Base attack bonus progression, and their rage ability gives them bonuses to blanket will saves instead of just will saves against fear like the fighter, Along with a Substantial bonus to Strength and constitution when raging. ( Not to mention you probably aren't going to use all your rages in a day later in your game )
As far as your stats are concerned, for your TWF Fighter, You have the right of it. Strength, Dex, and Con are your most important stats, wisdom being secondary for will saves. Strength will contribute to your damage, Dex will boost your armor class, Con will increase your HP quite a bit.
You'll obviously want the Two-Weapon Fighting feat, So that's one of your feats. For your other two You're level four, so you could take Improved Initiative to improve your chances of getting the first action with your dexterity, and Jaguar Pounce so that if you do get the first action you have a pretty good chance of getting the jump on someone and using the high crit ranges on your light weapons to get a crit off when the fight starts.
I believe using a non-light weapon in your main hand, and a light weapon like a dagger or shortsword in your off-hand is still considered standard with TWF, But since you'd be using two weapons you'd want your weapons to threaten more, so a mainhand Scimitar to vary up the types of damage you deal ( Slashing v. Piercing ) while giving you a larger crit range on your main hand would be the best.
So I've got based on the stats specified: Str: 18, Dex: 16, Con:21, Wiz: 12, Int:10, Cha:10
Feats: Two-Weapon Fighting, Double Slice, Two-Weapon defense, Weapon Focus: Scimitar, Weapon Specialization: Scimitar, Jaguar Pounce, Improved Initiative
That puts you with 4d10+20+4HP, With a 1d6+6 Main hand. If your opponent is flat-footed your crit range is 15-20/x2, When they aren't its 18-20/x2. Your offhand is 1d6+4.
This should deal enough damage in the first round to get an enemy to focus on you instead of on someone else in your party should you roll a crit. Later on when you hit level eight you can retrain your Jaugar Pounce Feat into Improved Critical.
Some other feats you may want to look into as you level are Furious Focus, Shield of Swings, and Pushing Assault, These work well with Critical builds as if you push a target more than 5ft away, they cant use a full-attack action during that round if they don't have pounce.