VMware workstation allows a maximum of 950GB. That's quite a bit more than VirtualPC 2007 allows. So what's my advise on sizing? As before, do the max.

Windows Server 2003R2 install makes 1,637,548,032 byte .vmdk. Still under 8% difference.

"But I don't want to pay the extra 117MB." Really? That's pretty cheap compared to what the space required to install a partition resizer later along with your time.

"But I'm only going to use this virt for a couple of things." Great. Then when you are done and delete it, you'll get a full refund of your extra space.

"I don't want my virt blowing up my main machine by causing it to run out of disk space." You could enable disk quotas.