MacDisk is pretty great at what it does..
Otherwise, as mentioned I believe, you can format to FAT32, and then both systems can read/write without a problem. Incidentally, you can format to FAT32 from either a PC or a mac.
Finally, I would say that a network drive should also work, but as the files are huge, you’ll likely not want to go that route.
Best free option is to use FAT32 on a large external drive, second best would be to format to HFS (or HFS+), and then use macdisk to access it on your PC. Either way should work great.