well. here's what I would do.

I'd buy a running engine. a complete running engine. make sure compression is up to snuff. Pull the head off and drop the oil pan. Make sure everything is nice looking. New head gasket. New oil pump, maybe even a high flow pump. Good tune up and powder its nose some and what not. Make sure it is running really well. Then boost that engine. With the power goals being less than 250, you ought to get that out of a stock engine. Get it tuned so it won't blow up. Tuning has a major part in the life of the engine. Then rock out with that for a while.
Then, I'd go to town with that other engine you've got. You're gonna get bored with 250 hp really fast and you'll be temped to turn up the boost. Just don't do it. I'm serious. Its like crack. You'll want more and more and more. So build yourself a new engine that can handle the abuse of higher boost.
That allows you to have more options. You don't have to worry about down time because you have a running car, driving everyday on a conservative tune. Gives you more time to save a few more pennies for better parts. Lets you do all kinds of things that you wouldn't have done the first time because you needed it to be cheap and now.
In the big picture, it is a bit more money, but you'll end up with a car that you're very happy with. You'll get used to driving with boost and you'll figure out what you like and don't like about the turbo you have and the intercooler set up and all of that. And since you have a car to drive, you can take your time on the new engine. That way it isn't a big deal if you take 6 months because you decided that you wanted to save up your pennies for forged internals. But either way, you have a back up engine just in case anything happens. Which, at those power levels, I highly doubt you'll have problems. Of course, it depends on the whole set up, but at less than 250 hp, you're talking less than 8 pounds.