Hi,
I think u should go for at least 6 to 7 partitions. Allocate 40-50Gb for C: and make the last two partions with the highest space. I will make ur drives performance good. If u have less partitions, then defragmentation will occur. And the drive will have to perform more read and write operations for a single partition, so go in for at least 6 partitions. Also, set the SWAP file on the last partition. It will give increased performance. Set it to 1.5Gb to 2GB.
Bye