You'll need more than "just the uppers and brake lines" and the "proportioning" valve wont need to change unless you really want to. You will need the upper control arms, and spindles/rotors (you can switch to bigger disk rotors but that will require some other parts also) and calipers (cores at the very least) and NEW brake lines, if your swapping break parts always use new hoses, much cheaper insurance than trying to scrounge up new front end parts.
Is it a good buy, that depends on what else your going/could scavange from it. You could probably find all the parts you need for the disk swap cheaper but you might have to put more time into searching for that stuff (whats your time worth to you?) where as you currently know where to find all the stuff you need and have a fair price for an entire car. What other goodies might you get from the car, is it a 318 car, what rear end is in it, what kinda shape is the sheetmetal in, hood, deck lid, front grill, bumpers, electrical stuff, is there keys for the locks/ignition and how well do they function? Personally if I had the 3 jacksons neccesary I would purchase it because I know I can always further part a vehicle down like that and get my money back and get the parts I want. Another question to ask yourself is, do I have the room to store said vehicle, while parting it down, that won't get you in trouble with neighbors or the city?
If you do get it, I would like a response regarding the condition of some of the aforementioned parts (pics maybe) as I have intrest in a few of them, might be able to work out a deal of some sorts.
BTW, gremlin, he's in Santa Clara, Ca.