As for armor, of course W/N will overpower N/W, but N/W can use health regeneration skills as their healing. However, the health regeneration skills (main ones are blood renewal, life siphon yeah lets go witht that), count as enchantments and hexes, so if they're removed, you're dead XD. Also, most hexes have casting times and can be interrupted (OUCH OUCH OUCH), not very cool

The W/N, on the other side, is stuck with Healing Signet. He only has 20 energy and using even 5 energy spells can be extremely deadly to their energy pool. Now, if you're relying on healing signet to survive, you are giong to run into problems. Ever heard of Mesmers or Rangers? The good side though is that you have more slots for damaging skills and can do more damage.
Speaking of skills, a N/W must and definately must have a healing skill or you will die. Curses, Blood are great trees for healing (with curses being more pvp since the cast times are usually longer) and should be used more to their maximum potential. THATS RIGHT MORE THAN YOUR ATTACK SKILL! If you can't heal, even though you may be interrupted or dehexified/enchantified, no healing is like you running naked with no weapon on into the battle field. There is, a very helpful thing about your healing methods. Most of your healing methods will do degeneration at the same time. Damage while you heal, is probably the best form of heal. Even a little can pressure ur opponent.
If you are looking for a weapon, the best is probably sword because of the extra conditions you can imply onto your opponent (muhahaha), and if you want to use tactics (for riposte + deadly riptoste, and maybe even some of the skills). Also, if you use sword, maybe you can throw in Virulence to do even mroe conditions XP. With a sword that isn't hard ha ha. If you're a fan of axe and hammer don't panic as well. Hammer can stun your opponent (less damage is always better), and axe can link up nice combos too

W/N's skills are probably only going to be Plaque touch, Healing Signet (or just rely on the monk), eh maybe ressurection sig + ATTACK SKILLS. Because you must rely on your damage skills to do damage, damage skills are going to make up for your lack of healing (not saying healing sigs bad or anything...). So if you can kill ur opponent quick, it will make your life easier.
I suggest Axe for a weapon, but you are free to pick whatever. Sword are good for conditions, and of course FT, but if you take too long to kill your opponent, tides will flip and YOU will be the one feeling the pain, you can go sword and virulence though, it doesn't cost too much and will rip your opponent apart. Hammer is great too, you can interrupt your opponent with knock downs and screw up their combos. Hey, knockdowns can screw up their healings as well

So all in all it comes mainly down to:
armor + melee damage versus energy + hexes + enchantments
Both have their ups and downs, but its a matter of opinion.
Please tell me more about these two classes if you know more (Hey, I'm learning too!).
YAYYYYYY