Whats the best build ?
I thought about a on dextery based sword using rogue.

Weapon :
If you want to go swords, that's fine. Look for Enhanced Effect on your weapon.

Armor :
Use tank scales or leather armors. Look for Enhanced Effect on these.

Charm :
Look for a Dexterity charm.

Accessory Slot charm :
Look for a heal charm with Enhanced Effect.

Stats :
Put your first 25 points into intelligence (until your reach 50)
Put the remaining points into Strength.

PM me with any other questions.

Yes, id get 100 dex with 55 gear, and stat rest into str. Depending on your gear you may need to stat some dexterity.
Also, if you are gone heal with secondary, id suggest you get a bit of Heal Master on either armor, weapon or charm.

Regards