i searched a bit, and you're right, the omegas are the lightest double boot. My current boots weigh in at 6.5 lbs for the pair! Also, most of the reviews said that the boot runs a bit narrow, so i think it'll be a good fit with my low volume, high arched feet.
I looked around for a good deal on the omegas. i found them on closeout at rockandsnow.com, and i had moosejaw pricematch, so i got a new pair for $200 + around $27 in points with my high altitude bonus!
I think i'll get them fitted professionally. I always wear my integral design vapor barriers since they also keep the bootie from getting any foot odor. my system is an injinji wool quarter sock, then the vapor liners, and then REI expedition weight socks, however with how warm these boots are suppose to be, i might switch to the standard REI or smartwool hiking socks if the expedition weight is too warm, and only use the expedition weight if im going to be standing in the cold for extended periods