Well let's look at this realistically. If you take a 14 STR, you're starting at +2 to hit. Thus you're going to want to get as much extra + to hit as possible. The Fighter Weapon Talent adds +1 to make it +3, and you'd most likely want to go with a +3 proficiency weapon, thus ending up with a +6 to hit at 1st level.
The question you now have to ask yourself is "what is more important to me, equal damage/defense footing, or overloading on the defensive side?" Because quite frankly... you could either go high CON for defense and then Great Weapon build to make up for the damage you lose for not having a bigger STR... or you could basically forsake damage for the most part and do the Guardian build for high AC on top of the high HP total. You are saying "I TRULY want to tank, and let the Strikers worry about knocking the enemy out." Because a 20 CON plus weapon & shield combo means it'll take a loooooooong time to knock you out of a fight.
For the sake of argument (and also because for my money makes the most sense), let's assume you are going as high defense as possible. This means the expectation is that you aren't going to massive amounts of damage, and thus what little focus you have on offense should be to make sure you do at least some damage.
Thus, first things first... one of your At-Wills should be Sure Strike. This is because it gives you an extra +2 to hit, for a grand total of +8. Yes, it only does 1[W] damage and no extra for STR... but those lost 2 damage points you might have gotten from a different at-will would do you no good if you are missing 10% more often because you're still trying to hit with a +6 rather than a +8. It's better to guarantee you get to do the base 1d8 or 1d10 (if we assume you go longsword or bastardsword for the +3 prof), than it is to worry about losing out on the extra 2 damage plus whatever little perk a different at-will would give you.
For your second at-will, you could go Brash Strike (from Martial Power) that would also give you the +8 to hit, would throw in the +2 damage for your STR score, but do both of this in exchange for granting combat advantage. But to be honest... effectively lowering your AC by 2 because of combat advantage (when you already have high AC and high HP) is probably not that big of a deal. If those two extra points of damage are important to you, you can use Brash Strike as needed.
Finally... your third at-will (if you stick with playing the human) will have to just deal with the fact you'll only be hitting with a +6 instead of a +8. Now to my mind... you'd want to select exploits that use your high CON score. And the ones that do that are the Invigorating exploits from Martial Power. Gaining 5 temp hp on any hit that is made by a power with the Invigorating keyword makes much more sense than selecting exploits that use your piddling STR score for their secondary effect (like Cleave and Reaping Strike do).
Wit those at-wills taken care of... your encounter and daily attack powers should usually try to follow the same pattern. Ones that either grant bonuses to hit (like Passing Attack, Villain's Menace or Shield Bash do), use your high CON in some fashion (like Knee Breaker does through the Invigorating keyword) or are Reliable (like Brute Strike, Comeback Strike or Lasting Threat) so it doesn't matter as much if you have a lower to hit since you can use the power again until you do.
You do that... and you'll at least hit somewhat often. And at the very least, hitting for only base weapon damage is still better than missing on higher potential damage exploits. Because after all, you're there to soak damage, not cause it.
Hope this helps.
