looking for rad replacement

HI, I'm new to the boards, and I'm really really lost.. Honestly I know little to nothing about cars. I am helping my boyfriend fix his 85 Monte Carlo SS. The thing he needs to continue getting it up and running again is a radiator. I'd perffer to get a NEW radiator for him, I know the likelyhood of finding a brand new radiator made specificly for an 85 monte ss is slim to none, but even if i could find something new :) that would fit his monte i'd be happy :) like I said i'm kinda lost as to where to get one, what companies are trusting to by from ect.. and how much would i end up spending on one? I'm trying to do this all on my own, I'm giving it to him as a Birthday present. Any help any of you can give me would begreatly appreciated :)
thanks guys :)

autozone, advance auto, any parts stores like that , i had my fan on my 88 shoot thru my radioator so i had to buy one, 75 bucks and it worked great