External Storage and Cluster Size

I have two external hard drive, one 160Gb and the other a 100Gb. I also have a 4Gb flash drive.

I have looked around and can never get a straight answer from google searches.

So to the question now. What would be the best format for these drives and what cluster size would be the best for them?

exFAT, FAT32, or NTFS? The drives will not be storing any large files. They are just pictures and music ranging anywhere from 2-15Mbs in size.

Edit: I am pretty sure the Flash drive needs to be FAT32 for my PS3 to support it. What would be the best cluster size for it?

Thank you for any help you can give and hopefully this will be a learning experience.