The Searcy Field grade rifles have been replaced with the PH model. The Field Searcy is a good working rifle, but as you say they are a little like a brick, with two barrels. The rifle would serve you well, and they are usually very accurate. The Merkel is a good rifle as well, and is a little more like the English style double, and for me they handle much better. That is not to say it wouldn't handle fine for you. The rifle has most likely been re-stocked for a lefty after it left Butch's shop. If I'm not mistaken when butch makes a left hand rifle it is a left hand all the way, including the trigger reverse,and top lever working the other way.

The new PH model is a far sleeker rifle, but is $9500 as of now, but the price is going up soon.

I'd not even look at the Blaser! The Krieghoffs are OK, if you can live with the cocking system. A friend of mine has a Krieghoff 500/416 double rifle, and he loves it, and it shoots well. Actually given the four rifles you have mentioned, I'd be looking at the Merkel I have one chambered for 470NE, and it is a very accurate, and good handleing rifle. The retail price for the Merkel Safari is MSR $10,516 US, and is worth the price they want, if ment, and the factory case comes with it!