Hello,
Putting a radius on the cutting edge will complicate cleaning out the corners at the bottom of a mortise where everything should meet at right angles. It will make paring easier though. I wonder why you would round the back instead of the bevel if your intention is to alter the radius of the cutting edge. It seems, along with reducing friction that it would make sharpening more difficult.
You do have more (and better) options than the Sorby one, that is unless you are trying to avoid added transportation. Dieter Schmid, in Berlin or Rudolph Dick, in Metten have very nice slicks. Their Japanese ones - which have hollow backs - might even be better suited to the kind of work you describe you are doing. If you were a Frenchman or German you would probably choose for a bisaiguë or demi-bisaiguë.
Greetings,
Don Wagstaff
