I wouldn't use the modern repro adapter plate they are selling now. It's too thin. The really old adaptor plates are made of approximately 14 gaga metal and will stand up to a good amount of torque.
Never had any problem with the thick rubber gasket that goes between the adaptor plate and engine block. As long as the adaptor plate is installed centered in the recess in the engine block, it won't leak and will last forever.
I wouldn't have a problem converting back to the original cannister and Purolator P-48 filter element, although some people have complained about having trouble with installation. To me, one is just as easy as the other, but I am a thin, wirey fellow and can get my hands in just about anywhere.