Multiple TLD of the same domain name? What to do (from an SEO perspective)?

Hey everyone,

I acquired an exact-match keyword .org domain name that, after much back linking, is now solidly somewhere in the middle of page 1 of the search results for that key phrase.

For illustration purposes, let's say my website name is www.internetmarketingrocks.org. (Not my real domain name. Just something I made up here as an example to help me illustrate my point.)

After much back linking, it is now ranked about #6 out of 62 million results, when someone types in "internet marketing rocks" into Google, and I am receiving a healthy amount of traffic from Google organic search for it.

Just the other day, I managed to acquire the domain name internetmarketingrocks.com from a domain auction. Right now it just points to one of those generic domain parking pages.

What is the most efficient way (I won't say "easiest", because I know there are no such things as short cuts in Internet marketing or SEO". I choose my words carefully and say "efficient" instead) to propel THIS domain to the top of page 1 for the same keyword as well?

1) Start from scratch and build a unique website with all unique content so that it doesn't look anything like my .org? This will take weeks or months to get to the same rank that my .org did. But if everyone agrees that this is the best option, I'll of course do it. Just wondering if there might be a better way. See the rest of the choices below.

2) Do a 302 redirect from my .com to my .org? I fail to see how this would help me from an SEO perspective.

3) Clone my .org website to make it look like a carbon copy of the original one? And clone all of my back links so that I have articles, social bookmarks, and blogs all identical and pointing to the new domain?

4) Add a back link from my .org to my .com? How does this help or hurt from an SEO perspective? Could someone please enlighten me?

5) Make .com into a clone of my .org, and then 302 redirect my .org to the new .com?

6) None of the above? If you choose this option, please specify your alternative?

My goal here is to get my .com to ALSO show up in the top 10 search results for this same keywords, without causing my .org to lose it's first page ranking.

Thank you all!