Hey Kid, what Joe was saying about these cars being expensive just to maintain isn't a lie, and you're already starting to feel resentment towards the car. The cooling system isn't even the most expensive part of maintaining these things. Something to keep in mind about his recommendation to sell the car. My own car always has three things broken on it, and when I fix one something else breaks immediately. Currently the three things that are broken don't affect driving it, so I'm purposely not fixing them.
That being said, are any of the junkyard cars you are pulling parts from 2003-2006 models? If so this car comes with an electric fan. You could get one of these fans for a low price and install it on the car, and you will know that it's a large enough fan to keep the car cool. If nothing else it can be wired to come on when the car is started. If you go this way you can put a hose from the inlet to the outlet on the hydraulic pump on your car and not have to worry about figuring out the belt routing. Going this way, you could probably get the cooling fan problem resolved for around 50 bucks or whatever the pullapart yard charges for electric fans. Going to have to hope someone has the wiring for the fan though, so they can state what needs to be wired where to make it work. Later on, when you've built up some money, you can investigate getting a way to control the fan correctly and a way to remove the rest of the fan hydraulics.
Here's the difficult part. The PCM regulates the alternator on the 1st gen LS. The problem with this is the way they regulated it, they determined that under engine condition X, alternator output Y is required, and that is all the alternator will put out. If you have extra electrical gear on the car, the alternator will NOT put out more power to run the extra load as it will on other cars. I don't know what the allowable margin is on the LS but as others have been able to run electric fans the alternator should be good for this but if you decide to put on much more, like a heavy duty sound system, you're not going to manage it. Swapping alternators for a larger one doesn't work either, because the PCM simply won't allow it to generate more power than it thinks it needs. So far nobody's been able to figure out a workaround for this issue.