Still have my cd keys stored on my bioware account, but definitely do not still have the discs. Is there a legal way to get the client off the internet without purchasing a new copy?

No.

You can download an image or dvd copy from lots of places. Downloading software you own licence for, shouldn't be illegal, anyway.
Of course i'm no lawyer.

No but on the bright side, you can pay a small amount here, get a new key to go with your old one and then have 2 copies you can legally play on a LAN

Problem with that is...

None of the downloads are just the discs, it's all discs and a built in crack or discs and cd keys on the discs.

I live in a dorm at a college, companies like bioware/atari specifically look for anyone connected to a torrent using a college IP address, then they just email the college and ask the college to deal with the problem and that way the company has to do almost nothing. If that happens I will lose my internet access entirely because my college has strict rules about piracy.

Also, $10 is not a small amount for me.

Then you're shit out of luck. Really though, 10 bucks shouldn't be that big of a deal unless you don't want to bother with setting up a paypal or getting a credit card. I'm currently going to grad school and probably making less money than most people out there, and I could easily afford 10 to buy the game.

What the hell do you mean, 'no'?

Just enter your old CD-keys into the nwncdkey.ini file in your NWN directory (simply replace the current keys with your original ones).

Works for me; all the premium modules I purchased years ago work flawlessly and authenticate just fine.

EDIT: Maybe I misunderstood what the OP meant... This works only if you bought the game from GOG (thus replacing the GOG keys with your own).

Pirating the game and then using your own keys? Illegal as hell, because you'd also still need a crack.
This also means you can't use either official patches or premium modules (they authenticate via internet).

You should just pay the 10 bucks and get the GOG version; that's what I did, since I can't find those CDs anymore.

You could borrow the discs use your keys and download the latest critical update patch which negates the need for a disc in the drive. Provided you could find someone to borrow them from. :)

That's what I did. I didn't even know any of my current friends had played the game until I tried asking.

it is against the law to download it from a non authorized distributer (ex: torrent) even if you have a legit set of keys. However, it is a CIVIL and not a CRIMINAL offense... the difference? you will not be arrested for it, but they can sue you and you will have to pay them a lot of money (effectively forcing you to declare bankruptcy).
Any website that allows people to promote such activities likewise is a prime target, this is why most forums ban you for telling someone to get a crack. So, it is against the forum's TOS and can earn you a ban to tell someone to get a copy via a nonlicensed distributer. All three statements are false.
1. installing official patches (via the auto updater) does even check your keys, it will work regardless.
2. running a premium module only looks at your keys, it will work as long as your key is legitimate, it doesn't know or care what the source of your disk is.
3. while most games would require a no-cd crack, nwn1 has had the CD check removed beginning with patch 1.61 IIRC, it only requires that you have legit keys. thus for nwn1 it will work without a crack.

So, it is against the law, but a civil not criminal offense, it will work, but it is not allowed, and you are risking a virus as well as breaking the law by doing so. so don't do it.