Another option, besides the CV buy, is to invest in bombers.
Do a strat. bomb on London G1 (with 2 bombers), and do another one with 2 + 2 on G2 (with a G1 buy of 2 bombers and whatever else your heart desires for 6 IPCs).
In my opinion, it’s the better option because once you’re through taking London, extra bombers are far more useful against the USSR than a carrier.