If security isn't an issue, you should be fine going with FAT32. However, you did mention that one function of this pc is to be a server with several clients. So, unless you plan on exposing the entire system to any traffic that may cross, you may want to reconsider.
Yes, it's true that FAT32 can perform equally if not faster than NTFS on smaller partitions. However, this has only been shown in some benchmarks, which actually show more of a trend than a certainty. In other words, don't pick FAT32 under the assumption that your system will see a speed benefit. Depending on the type of apps/processes running, speed may be on the side of NTFS in some cases.
Just my 2¢
~cdogg
"The secret to creativity is knowing how to hide your sources."
- A. Einstein