I bought a radio-telescope book from Willmann-Bell about 3 years ago. I took it in to work (at a place that does radar things) and it promptly disappeared so I don't remember the name of it but it was quite detailed in what it described and I was considering doing the interfrometer at 2.4Ghz (what we were working in) just to see how well it worked. I wish I could be more specific but that's what life is. The project is quite doable but remember that your telescope is not going to have much resolution as you're probably not going to be able to get the elements far enough apart to get a resolution below a few degrees. You may also want to experiment with using a radio to transmit the signal from a distant antenna to your base station. Have fun with the project! It will work, even if you only are able to detect the center of the galaxy and the sun and moon.