go for option 1, take out a credit card in the US and if needed credit the odd AA flight to your BA account where possible to bring your BA balance up further.

LAX-LHR-DEL-LHR-LAX would also give you your 4 BA sectors and 480 tp's. Depending on your AA travel plans you could credit 3 or 4 AA flights (assuming your flying in AA domestic first) to your BA account and become a BA silver card holder fairly easily.

CS