Hulyss - I would take half of what you have on offer, even a tenth as long as the EVF - which incidentally I agree should be a clip on giving you flexibility to use either an EVF or an optical finder - is developed and as long as I can have one body and 3-4 lenses, one of which needs to be equivalent to 21mm. I don't even need fast lenses. I'll use a tripod or as they are leaf shutters I can shoot them down to 1/30th with ease. And it must be the Merrill sensor. Please!
Some might say that poooor Sigma corporation can't make it but I say Sigma corporation CAN make it, around 70% of it. No need to be a rocket scientist to see, in this speculation, that 70% of it is largely possible within a year of work for any kind of electromechanical engineer. Just to make a prototype.
For sure, a new processor is needed. The EVF is completely possible and the money is here !! Kill this damn SA mount, kill the SD camera line and you'll save money, for sure.
The lenses already exist on the DP. Put a stiff mount on them and power it with the body : You have your First compact LF interchangeable lenses. This is what I call a buzz. Make some bigger ones like f1.2 primes and your ok. here we speak for an APS-C model.
For FF... SIGMA know they need to do one. They even know they are obliged to do one.
There is one basic rule, outside pixel world, that many photographers seems to ignore or denies: "The less the enlargement the better the picture".
FF is the way, even with less pixels than Merrill, picture will be better.
Even Kasuto Yamaki liked my idea. Have a look in the past, January 2014: