large file transfer petween pics

I have an application where I need to move large amounts of data wirelessly.
The data rate is going to be 115Kbaud, with 128 byte packets. I have worked out all the RF design, but here's the rub... The files can be up to 256 KBytes in size.
Has anyone attempted large file, high speed transfer? If so, what kind of memory did you use to hold the streaming data while the link was downloading the file? It looks like some of the flash memory suited to the task, will be too slow to write to without being overrun.
Any ideas?

Thanks,
Ron

FRAM could be great IMHO... but at that speed.. i'm not 100% sure