What's wrong with the mount that came with the airplane? And what is that, a WM Dago red? Looks like you're using a Saito .72, or is it an 82? If you're worried about the mount being strong enough, I have a Saito .82 in a WM Zen 50, probablly uses same mount. Plenty strong.

As you're probablly noticed, engine mount is off-center because the firewall has built-in thrust. The off-center mount allows the engine shaft to be centered in teh cowl.

As for the fuel tank being higher than the carb, you're gonna prime the engine every time you fuel. Just make sure the throttle is all the way closed. I have one plane with a Saito 4 stroke where the fuel tank is quite a bit higher than the carb. The engine just plain runs rich at idle, no way to close the idle screw enough to lean it out because of siphon effect. But the engine idles fine, transitions great, no problems. No onboard glow, just an OS "F" plug.

Andy