ls.vtec is chepper by far
up the compression by a vtec head and kit the vtec kit from golden eagle
get some cams and valve springs and retianters and a decent intake and headers and then get it tuned and you will be able to take it to 8000rpm

B20 vtec is a lot more $$$$
crank rods pistion then build the head as menchioned above and you have a 2.0ls/vtec
that can go to 9200prm but i take it to 8300 after its tuned to be safe
i have to get mine tuned on friday and see wat power it makes compared to the 1.8 ls/vtec

over all its up to you and how far u r taking each build and budget