I've never had a problem with a fuel DOT leaking.

As far as brands, I often use the DuBro:

http://www3.towerhobbies.com/cgi-bin...&I=LXAHE1&P=SM

The DuBro type have a receptacle that glues to the cowl.

Or these:

http://www.horizonhobby.com/Products...?ProdID=HAN115

On these, the receptacle screws onto the cowl