London on AA, then either points or $$ to upgrade to BLR. BA is good at selling upgrades at the desk. Have done the flight multiple times. Long layover in T5 (early morning arrival, evening departure). With EXP cool your heels in the T5 First lounge. Better yet, buy J and upgrade to F (if they are flying the 747 not the 777 which does not have it) and do the CR in T5.