If you format the second disk with the exFAT filesystem both operating systems can read and write to it. However after looking around, not many people have had success with it contiuning to work for long periods of time; the exFAT format just wasn't made for that use. Here's one forum that talked about this exact issue.
http://forums.macrumors.com/showthread.php?t=1134183
In my case, I think I'm going to end up simply making four partitions: 2 SSD partitions, one HFS+ and one NTFS, and 2 spinning disk partitions, one HFS+ and one NTFS.
One workround is installing a third party product within your Win7 bootcamp OS that will allow you to read and write on HFS+ (Mac OS Extended) formatted file systems. Then you could simply format your larger second drive as HFS+ and be done. I'm also considering that myself, but will only do so if I run into space issues cause I'm cheap.
I will post back up with my results when I get it finished.
Cheers all