Research MBA Programs

I have been studying for my GMAT since 15th August 2015.

I am a indian male,aged 38 yrs graduated with Civil Engineering. I have got a 15 yrs work ex & I am working with a big corporate on a senior position. I am in to granting approvals for funding real estate projects. Now I want to take my career to a greater level & hence I am planning to do a MBA and that to a FULL TIME.At present my GMAT scores are hovering around 580.I am targeting around 650.
I want to go ONLY to TOP M7 US SCHOOLS

But I am struck up in one query.

Whether I should take a 1 year MBA or 2 Years MBA.I am aware that 1 yr would need lesser cost in terms of finance & opportunity .
But Is the one yr MBA at Chicago Booth or at the top M7 have the same value/recognition/prospects/employment opportunities and post MBA salary as that of a 2 yr MBA.

Would need your advice

Scoring a 650 GMAT will not be a guaranteed trip to a top 7 school. In fact it will put you below the average at many of them. Why don't you consider an executive program, especially because you have so much work experience? It will allow you to keep working and your GMAT will become less important. Not many top schools even offer a 1 year program. You might need to expand your list a bit.