Belts are the weakest of the timing options though and require preventative maintenance. They don't always handle high rpm well and they do flex and stretch the most out of all the options. If you were to go the gilmer drive route, I'd put a dynamic tensioner in the system. There is no way a static tensioner can take up all the slack that will happen as you increase rpms. It's amazing just how much a belt can stretch.
I favor the gear drive route, rock solid timing and the most reliable option. Sealing the engine properly can be done and while I don't personally have a FE right now, isn't the main oil leakage problem the rear main cap?