You should refer to the other thread you started, plenty of people who posted in there have done this conversion. Also look to forced induction, there are many threads explaining what to do, with pics. At the end of the day, unless you can convince someone to help you for seriously low money (like 1k) the reality is the rb25 is just going to be out of your price range. You don't know enough about your car/engines to do this yourself, regardless of how much you read. If I was you, i'd take my car to a mechanic and get a new rb20 put in, and do as much else as you can with your money whilst it's there....if you want to spend the rest of the money that is. Otherwise you'll end up with a car thats off the road for a long, long time.
Just my 2c
Matt