It doesn't matter. The only practical thing to consider is that if there is more than one primary partition on any one system they will be assigned drive letters before any extended partitions/logical drives. And Windows will only let you create on primary partition per hard disk drive. You can create a primary and one extended if you want. Like I said, other than the one practical consideration I mentioned, it doesn't matter.
[EDIT]Also, keep in mind final usable space will be about 232GB. So you won't get two 125GB partitions. If you create your first partition as 125GB the remaining one will be about 108GB. See the chart
here.
\Dan