Banner managers
 

Which ones are perfect or should I go with a custom solution?

:)

If you have a ton of traffic and you have the power (or even a seperate dedicated server) you can't beat phpadsnew... and it is free. It is a bit of a resource hog though, especially if you enable detailed stats and geo targeting.

phpmyadsnew :2 cents: go with the best

is it really that resource eating?
I am no real of such scripts.

I use centralAd(www.centralad.com) and absolutely love it.
you can get better than this