An ls/vtec does not produce impressive horsepower results unless it is built with the proper components by an experienced builder.
I would recommend you purchase a clean low milage ls swap, then look into putting a QUALITY turbo kit together.
For more information on ls/vtec setups, check out
http://hondaswap.com they have a good intro article.
For more information on turbo setups etc, do some reading on honda-tech.com
Rule of thumb: Do research before you listen to your friends.
Good Luck.