stock answer v. searchandyou'llreadthisathousandtimesover:

Which is more reliable? Impossible question to answer, heres why. A b16a or b18c swap seems like the most reliable solution because you're just putting another bone-stock factory built honda motor in. Of course, you're buying a motor you know nothing about... you don't know how many miles are on it, how it was treated or maintained, or if there is anything wrong with it. But what about turbo? Tons of people have reliably turboed their cars and piled the miles on with no problems, but then tons of people haven't. There might be something inherently unreliabe about turboing a motor that was never intended to be used that way, but that "problem" is dwarfed by the unreliability caused by faulty installation, tuning, parts selection and research.

Bottom line: Decide what you want, and get it. Be careful and take your time, it will only be as reliable as you make it.

:edit: in response to your last post, if you want to make it fast, expect fuel economy to suffer.