1990 Burb radiator replacement

[CHANROB]

I am needing to replace my radiator for my 1990 2500 Suburban 4X4 5.7L. I was wondering if anyone might have any suggestions? I live and drive locally in So. Cali., so the temp is mostly in the 60- 80 degree range. I see there are plastic ones, which dont sound very bomb proof to me, but I have never replaced a radiator before, so I dont really even know where to begin. By the way, my current radiator has a tiny pinhole (stop leak products are not an option), and I was wondering if this might be the cause of my temp gauge to be fluctuating from 210 (mid range) to 260 (red line/overheat)? I have yet to overheat, but I dont like the redlinning! Thanks in advance. Rob, 40, So. Ca.