I'm with PontiacGP on this. If you really want to find out what kind of shape a car is in, you need to go and look at it in person. Most sellers won't tell you about the bad points of the car that they're selling, so you need to go and find out for yourself. If the '84 SS needs a floor, and you want to repair it properly, its going to be a fairly major undertaking, and chances are that there is more rust than that. Plus, as pointed out above, the car will need some correct wheels, cleaning, and probably other work, so its not much of a bargain. As for the '87 SS, judging from the area where the seller is located, chances are that the car has been broken into, and there is some rust showing in the photos, so there's probably more that isn't showing. It seems to me that you're in a similiar situation to YGspider, that you want to find a car as soon as possible, which may not be a good thing. In my opinion, your best bet would be to take your time, go and look at cars you're interested in, in person. Try to get a car with the least amount of rust as possible. Mechanical work is generally easier and cheaper than bodywork, and it will allow you to keep your interest in the car better. Plus, I've usually found that there can be alot of enjoyment in the anticipation of the hunt, and once you've found a car, that enjoyment is gone.
If what I've said doesn't matter to you, and you're looking for a G body project, I've got an '86 Grand Prix 2+2 that I'll sell you. Let me know. Good luck.