| You'll generally be able to keep the stiffer feel using a new set of strings of any type that has never been tuned up to 440. Of course, heavier strings will feel better. They also sound better at that pitch.
Once you bring strings up to standard pitch, and then, detune them back down that far, they will feel flabbier, as you have stretched them out.
If you do it repeatedly, they'll eventually sound like trash or even break.
If it is a setup you end up keeping, you'll have to loosen the truss as the strings will create less tension detuned like that.
If you decide to go with a fiver set and throw out the G, you should get a the lightest set you can find. Even then you may have to tighten the trussrod a bit to offset the additional tension of being tuned up a 1/2 step. | 
I'm currently playing off of ernie ball powerslinkies on my fender p-deluxe and i can tune down as far as a somewhat floppy low f#. i'm pretty sure if i took the ghs strings i'd have little to no problem tuning down anotehr halfstep from what i usually play (Drop D)
