first off if you friend is only running high 15s then he does not know how to drive, why not get someone who actually know how to drive and let them race it and see what it runs. it should be runnin low 15s to high 14s.
its not that easy to do lsvtec, yeah your right when you say you gotta add the oil line but you also have to plug the hole in the b16 head, then drill a hole for the dowel pins on the ls block. you can probably get a block for like $300. BUT if you dont build your ls block up then i would not take it above 7000 rpm because if you do then your ls will only last a few months of racing. i say if you put a b16 oil pump on your ls for more flow adn put the b16 oil squirter on, then buy some cheap upgraded rods and pistons. then your alot better off, but i would still only take the engine up to 7500 rpm and nothing more.