Will I be warm in this at 20 F

I'm not very familiar with those jackets, but I think I'd be plenty warm at 20F. The down pants and booties are nice, but I've been just a little chilly without them down to 10F. I know I would want to at least bring a pair of medium wool socks, but my toes get cold easily. I also bring an acrylic knit balaclava.

Just to clear it up my FF Daybreak has 2.8oz of 900 fill down. Sort of between a MB UL/EX Inner Jacket and the Alpine Light.
It's not as lofty as my MB Alpine Light though. I'd say it's about 3/4" single side loft.
The Daybreak is a great light down jacket but I'm concerned it might not be enough.
Or will I be fine….

I have the Daybreak as well. Now I am a cold person, but I only bring it when I don't think the temperatures will drop much below 40 if that is my only insulation. Judging by this post

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=18950

I would have to put the FF jacket at a max of 2.25 clo since it has a little more down than the Montbell UL Down Inner. Using that information I would look at this post.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=9378

This chart seems to show that a clo of at least 4 is recommended for 20 degrees. I would maybe take the the Alpine Light since it has an ounce more down for not too much more weight. If you bring the the FF jacket you can always go to bed early if you get too cold sitting around. I recommend bookmarking those two threads as I have found them invaluable.

That would be plenty of insulation for me in 20deg. with that clothes list i would take a 35deg bag. however, i know several people who would consider this more of a 35deg clothing list, so it's very personal. oh, and dont forget gloves!! have fun, be a little cold, you wont die!! have fun!

Yes I have gloves, Just forgot to list them
I'll have my usual possum down gloves and some MLD eEvent rain mitts.

I have trolled all over gear lists etc and it's just hard as I'm looking at less of a jacket than is normal… But those down panst have to count for something, Right ?

I know I can use the MB Alpine Light and did do that last year and was toasty @20 F. But I'm now packing down pants and the MB parka is quite a bit heavier than the FF (180grams more, I know I'm a gram wieny) But I wouldn't need my blackrock hat if I took the MB.

Sounds like plenty to me.