NTFS Write Support

Is there any 3rd part tool that will allow my new mac to write to an ntfs partition?

FAT32 doesnt support files larger then 4GB's and I'll be using an external USB that I connect to a lot of windows boxes for work purposes.

I think you are stuck! I am not aware of any 3rd party Mac tools that will write NTFS. HOWEVER, there are third party PC tools that will write Apple HFS+. Perhaps this is your answer, although such tools (MacOpener is one) are commercial software packages and are not cheap.

From what I've seen, the only way to WRITE to an NTFS partition is to attach it to a Windows system and connect to it via SMB. Then you can write to it over the network.