You seem to of skipped over the METV (multiple entry tourist visa) as an option.
You can get a total stay of almost 9 months from it by doing 2 border hops with the last one done just before the visa expires.
That is a total of the first entry of 60 days and a 30 day extension, border hop for a new 60 days +30 day extension and repeat border hop just before the visa expires +30 day extension.