in all honesty, a b18 will give u better torque... but how come its cheaper? i thought its more expensive? and for that price i highly doubt its LSD. i was considering the two when i did my transplant, but i opted for the 1.6 (silly me).
as far as the mounting is concern, i believe it shouldnt drive u to opt for the other, because its only a small issue which can be resolved by getting another set of engine mountings. wont cost a bomb either... so if u want pure power, i believe the b18 will satisfy ur hunger.. however the b16 is quite powerful also... kekeke
as far as endorsement is concerns, both no problems..