What is the most minimalist complement to a m43 system?

Alex Notpro wrote:

I bought into Micro Four Thirds a couple of months ago, with an E-PM2, to complement my Nikon D7000 DSLR (APS-C format).

Then in my last trip overseas, I packed both cameras but wound up selling the DSLR to a local towards the end of the trip, with plans to replace it when getting back to the USA.

Now I'm pondering over this question: What would be the most minimalistic setup that complement's m43's weaknesses as a primary system, but no more?

My first thought is, a Nikon D700 (old full-frame DSLR which is now relatively cheap) with just two lenses: 85mm f/1.8 and 70-300 VR zoom. I am not familiar with other manufacturer's line-ups but would like suggestions.

The idea is to plug the holes of Narrow-DOF and Low-Light Action which are MFT's soft spots, without spending a bundle on this DSLR "second camera" system.

As to the type of photos/usage - I'm an enthusiast who enjoys honing my skills over the full coverage over any type of photographic subject that may come up. I shoot primarily family/travel but I strive to find more challenging situations wherever I can.

Thoughts?

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