Cronic

As has been stated before. It's not the amount of boost that you run in the engine, it's how much horsepower, and how much combustion pressure is in the cylinders.
As the latter is a bit harder to calculate, the bottom end of a WELL tuned D series engine can hold 300ish whp. For a decent amount of time > 1 year.

Now, if you want a safe, moderate tune, and know the engine will last as long as you want it to (with in reason) I would say 250whp is about where you will want to be. With a low 11:1 a/f ratio and moderate timing.

To figure out the best turbo for your needs is a pretty difficult question to ask.
I would first have to ask you, how much power are you wanting to make? How responsive do you want the turbo to be? Do you mind lag? Is this going to be a street car/drag car/auto-x? How deep are your pockets?

With out knowing anything, from personal experience: SOHC VTEC engines love turbo, from small to medium. Even though they have very low displacment, they still spool well. The heads seem to be designed for just this thing. For a street car, with wanting little to no lag. I would suggest going with a straight t3, 50 to 60 trim. This will allow you to make around 220-250whp @ 12-16psi (depending on many things) and have very little lag. (2500-3000rpm full boost).

If you're wanting to make 250whp easy, and have room for more, with moderate lag. I would suggest going for a t3/t4 50 trim with a .48 a/r on the hot side. This will allow you to make full boost from 3500-4000rpm and make 250whp on lower boost pressures. Somewhere around 10-12psi.

Of course there are much more radical and high end turbos you can get, whichi spool fast, and provide much more power potential, but I'll save that for another time.