Tees and dots are a great way to go--no clamps, no air leaks, no fuel leaks in my experience. If you go to a pattern meet you'll see fuel dots all over the place, and these guys want their planes to be foolproof and reliable.

Another option is a pair of ell fittings on the outside of the fuselage (or some guys use two pairs). Central Hobbies has them, as does my LHS. The fuel line and pressure line from the engine go to each of a pair of ells, connecting inside the fuselage, with the ell opening outside. Another pair of lines from the tank--clunk line and vent line--come out of the fuselage (through drilled holes or through an opposing pair of ell fittings) and connect to the engine line fittings (clunk to YS pump in, vent to check valve).

When you fuel up, you disconnect both lines and fill the tank through the clunk line. When spillage comes out the vent line, you connect both lines to the ells and now you have a full tank and a closed up system between tank & engine. When your flight is over, be sure to disconnect the pressure line to relieve the pressure in the tank. If you disconnect the clunk line first, you'll have a strong jet of fuel all over yourself, your model, and any bystanders.

I've tried all the other fuelers. The GP and Dubro fuelers are simply defective designs. I've never had one that didn't stick open after a few fillings. The Sullivan fueler never failed me, but the dots or ells are the ultimate in simplicity and reliability.