i would suggest vtec...
boost on a b20 is not so good bec of the 84mm bore...
it is thinner and weaker than other b series blocks with a 81mm bore...
but with a good tune you would be fine either way...

if you go boost you will see a bigger hp gain...
but vtec would prob be a lil more reliable...
its on you tho man...

personally i dont suggest boost on a b20