What Sigma ILC has the best quality?

So I'm curious:

Is the SD-1 Merrill still the flagship product or is there other cameras that have since come out that do a better job?

Anyone know if there is a full-frame Faveon planned?

I've been in photography for a mere 5 months.  I started off with a Sony A65.  Its become clear that I have a far too discerning eye for IQ than most other novices.  As such I've decided to plop down up to 5 grand on a new camera.  The two choices were primarily the Canon 5D MkIII and the  Sony A99.  

But wait!  I see Michael Reichmann's A99 Field Report mentioning the AA filter and how it blurs images.  So I start to Google which cameras don't use the Bayer filter.  I find the Fuji X series, but I've already discovered they suffer other problems due to the wider uneven spaces between pixels.  Then I find a review for the Sigma SD1.  Quite impressed.  Then for over 4 hours yesterday I scour Flickr and other sites looking at photos taken with the SD1 and every one of them are just amazing quality.  What really blows my mind is when I view at 100% - I see exactly what I expect to see.

So the SD-1 is a few years old.  I've read about a lot of problems with it, and the fact that virtually no software can develop the RAWs (outside of the bundled).  But despite all of this - I'm still quite intrigued.

The price demanded for the SD-1 is pretty steep (even after its price reduction) considering its lack of features and the fact that once you cut through the 42MP marketing mumbo jumbo its only a 15MP APS-C size sensor.

Dan