Your kit already has the knightly sheen...it seems to me that armor is optional; just depends on how deep you want to get into your persona. Glad to hear the neck pain's gone away...I know in the past for me, it always took a couple of weekends before my body got re-acclimated to the weight.
This year, I decided to be proactive and put together a workout regimen that focused on my shoulders, back and legs since those were the problem areas I'd noticed in years past. Mostly free weights, I worked in squats, deadlifts, leg and core workouts - as Sir Edward stated, your posture has a lot to do with how your body's going to feel after being laden down with armor all day.
Hitting the lower back has been especially beneficial for me as I've always had poor posture but I'm more aware of it now. Getting an area like the neck 'used' to carrying weight depends on how strong it is in the first place. Sir Wolf's right, you can definitely end up with a pinched nerve if you're not careful...you might try something like strapping on a 18 gauge display helm and wear it for like an hour a day until you no longer notice that you're wearing one, then graduate to the full-on 16 gauge helm. Just an idea...its what I do; but then, I'll wear various bits of armor around the house just because I like to. Luckily for me, my wife finds it adorable and somewhat sexy so...guess I'm good. Nothing worse than having your spouse look at you like you've grown a third eye or something to take the fun out of things. lol