Thanks. When I went through and left default settings, it selected 128kB. I went back to 256kB and created it, though I'm considering trashing it and going to the 512kB since it does seem like a better size for 99% of the files being over 10GB. It's all my movies that I digitized and the server is a personal Plex server. Mostly played within the home, but I do have a couple of friends that I've given access to as well.
I'll actually be running two RAID 5 groups, but each on their own controller. An LSI 9260-8i, and an IBM ServeRAID M5015, which is basically a rebranded LSI 9260-8i that I just bought on Amazon for $50. I thought my LSI card was dying, so I bought a new card. Turns out that it was just overheating, which seems to be a common problem. I hooked up a 40mm fan to each of them, put on better TIM and haven't had any problems since. And for $50, having a second card is definitely worth it.
It is saying it will take over 2 days to initialize, which I expected. I'm trying to find out if I can format and use it in the mean time, or if I need to wait for it to finish initializing. So far Google turns up that since it's a controller card and a hardware RAID, it doesn't even need to be initialized. But same with the stripe search, all the hits are really old.