since dual swords requires a bit more dex then other weapons (other then claw), you kinda want to make your str and dex balance, or enough to wear your weapon. Then put con to every other level, or one for every level. You can stop putting con, when you think its enough, or around 80-90, somewhere there. Remeber dual swords need dex, so you may not be wearing good heavy armor at the level you are suppose to, but that doesnt mean you should go for a light armor. Stick with low heavy armor.

Last bit of words, follow your weapon requirments first, its better to get better weapons at the level your suppose to, then trying to balance the stats.

So each level you should pump, 2 str 2 dex and 1 con, until higher level, then you can focus on pumping ethier more dex for hit,evade,cric, and speed. Or pump strength for more damage and better armor

Im not really clea ron one sword, but the requires are the same. So you can still stick with the 2 str 2 dex and one con build, and still wear everything. But you have to remeber con helps you survive, and since you are not rich in the begin to afford item mall stuff (unless you pay real money), then you should problary stick tot the problary, until you think its enough