Rebuild or new motor?

I have a '94 Integra LS with 140K miles on it. I want a motor with LOW miles (30-40K), so I'll probably end up buyin one from an importer (LS motor, because I wanna turbo it). Someone told me to rebuild it though, and that got me thinking. If I rebuild it, I can do a custom motor, with a bored and sleeved block, new tranny, etc. It costs more, but then again I'd be doing that kind of stuff in the long run anyway. So, I was wondering what you all think. Rebuild, or just a new LS?