Ahhhhh - gotta love free software that costs hundreds of pounds per year for security updates
You have a couple of options...
1. Use your companies servers to download the updates, take those home on CD and apply (or scp them home - whatever)
2. Use a different up2date source. I'm not 100% sure that whitebox linux will work well with RPM versioning though. For example, if you have RHEL3 ES UPDATE3 the version numbers of some RPMS (due to updates, etc.) will be different than for RHEL3 ES UPDATE2. The last I looked, whitebox had successfully caught up with UPDATE2.
3. Go for Fedora at home and accept that there may be slight differences, but you'll probably get a better desktop experience out of the deal.
4. Talk to Red Hat about a home licence similar to what Microsoft offers to their Enterprise users - i.e. you get to have the software at home, fully working (including updates) for a negligible fee to cover media. They'll probably just say no, but it's worth a try
HTH