Based on that bow I made with 0.040 glass, I'd say 0.435 for a total stack. If it ends up a little heavy, you can narrow the limbs a little to reduce weight.
Yes, my limbs are the same length. Once I get a string on it, I check the tiller. The majority of the time one of the two limbs will be a little bit stiffer (1/8" to 1/4") than the other and I then designate the stiffer one the bottom limb and finish it on out from there.