[CentOS-mirror] Replacing my mirror server

I've just ordered a new server to replace centos.zanker.org (UK mirror) - this will have plenty of disk space allowing me to host a full mirror.

I'm just wondering what's the best version of CentOS to install on it, bearing in mind that I might want to host the DVDs at some point. I'll need a version of apache that supports files greater than 2GB - will the CentOS 5.1 apache be OK for this? Should I install the 32-bit or 64-bit CentOS?

I'd also be interested to know what people who host the DVDs are seeing bandwidth-wise - I have 3TB a month to play with...

Thanks in advance,

Mike