I would go the simple route.
1, Use this program's bootable CD
(on the left side of the webpage) and clear the whole disk
2. Then define a partition large enough for the Windows7 installation. The size will depend on your requirements but for normal use (no games), 50GBs should suffice.
3. Then set this partition to primary, active (using the same CD program - in Partition tab > Modify)
4. Leave the rest of the disk free. It is easy to define your other partitions in that freespace with Disk Management once you have Windows 7 up and running. Data Partition
5. Install Windows 7 in that one partition you defined. This way you will get your MBR in the same partition and avoid the seperate 100MB boot partition.
PS: if you have other disks on the system (possibly with other operating systems) you should physically disconnect them during this operation.