Is there a good variation of New Armor and Weapons?
Alot, new Vampire armor, Dawnguard armor (light/heavy), both have varying color skins, new Falmer Armor (Heavy), and Ancient Falmer Armor (Snow Elf, Light), Auriel's Shield, Aetherium Staff/Shield/Crown, Auriel's Bow, Zephyr, Harkon's Sword, Shellbug Chitin Helm, Dawnguard Axe/Warhammer, Dawnguard Shield, Runed Shield/Hammer, just to name a few.
Ah and the real question: Do you have to be dragonborn to access Dawnguard?
I haven't personally tested this, but alot of people over at the beta forums confirmed to us that you can do start and finish the questline without ever touching the Main Quest. You can also start the Dawnguard questline at level 1 by going directly to the Fort, rather than waiting for level 10 for rumors to pop up.