Welcome to the CBL/CN camp
If you're looking to cut 20lbs in 7 weeks, I'd look in to Carb nite with once or twice weekly carb refeeds. Strength may take a little hit compared to CBL, but you'll be a lot lot leaner compared to running CBL.
Just my $0.02
Fen and myself probably have the most experience with CN/CBL on this forum so feel free to reach out to either of us!