Try a battlemind. Constitution primary means you can max durablity and to hit at the same time. With Conductive defense you get a lvl1 at-will that targets reflex. The powerpoint mechanic is wonderfully easy to use and gives you much more flexibility than encounter powers.
Only downside is that all the reactive powers can slow down play. If you want faster play, go with a knight. It's a solid class, even if it is a little dull.
Battlemind looks interesting but it seems to me that the general consensus is that there is a period of time during heroic where you are just meh. Maybe I'm wrong. Swordmage is a maybe, I'm liking the solidity of a knight.
Maybe I'm really underestimating the importantce of a INT primary, I was going to go Dragonborn/Kulkor Arms Master and try to abuse the pushing and proning etc.... You made me rethink the INT primary situation but I'll still linger on it. Is shielding swordmage able bodied to be a primary defender?The eladrin frost build the guide has up looks apealing, maybe I'll check out assualt.
I played a battlemind as the only defender in a 6 pc party from 1-4 lvl. He was awesome with one exception. Daze was the absolute worst. The battlemind relies on reactions and daze completely robs you of you ability to do anything. Immobilize never hurt me that much but daze just sucked.
But I think it kinda sucks for any defender. So if you can afford it, get a 15 wisdom and take the superior will feat so you can save at the beginning of your turn.