avs2002ie, I am surprised you can't correct your eyesight using fully corrective spectacles. Class 1 FAA medical is very stringent (you'll need that for your ATPL) but corrective lenses are allowed, to the extent that if your current pair is not up to standard, you have about 7 days from the initial examination to prescribe a better pair for a re-test (in the USA anyway).
As you know, the J1 program is expiring soon. I note you did not mention the possibility of hour-building under that, as in reality there is none. The US economy is so bad that instructors aren't moving up to the regionals and therefore graduated students are hardly moving up to get instructor vacancies. That applies across the entire country.
Delta is no longer issuing J visas and their website is out of date (presumably you haven't contacted them yet and you don't know). However, you may still be able to get an M visa there. Flight Safety is similarly a sausage factory, so there's very little difference between the two. Take your pick.