Ken - I have used the SAITO .30 in many planes, including the Nobler, Argus, Ringmaster and Sterling Mustang (profile). I even flew my profile Cardinal with one.
I also have on in my Little Cherokee which has a Nobler size wing.
It does extremely well in all these applications.
I cannot comment on the Shark as I have never seen one.
The .30 does in fact have the breather nipple toward the front, opposite the cam housing. Route it somewhere outside the cowl.
Figure on 2 1/2 ounces of fuel AFTER the engine is completely broken in.
Regarding props, you have to match up to the plane but I would start with 9, 9 1/2 & 10 inch diameters, with pitch in the 5 to 7 inch range. The APC and Master Airscrew are excellent.
Bob Z.