Re: CFFB or CFWF?
My brother was in a similar situation: 5'11" 138#. I put him on CFWF, starting light, eating a LOT, drinking a LOT of milk and now, 6 weeks later, he's up to 160#. His strength has been going through the roof and the 2 metcons a week aren't too taxing for him to recover in time to continue making strength gains.
As far as metcons go, I've been programming a mix of sled drags, tire flips, clean and jerks, power snatches, kettlebell swings, etc. relatively heavy, but really focusing on technique as his strength comes along.
I really don't think you can go wrong with either program.