Alright, I'm back from the Holiday weekend and I have some more information. After a lot of reading and also looking at my room, i decided that i'm going to go with a larger enclosure. However, I'm toying with the idea of putting the woofer on the 48''x24'' side, not the 24''x24'' side. This works a lot better with how my room is set up.
I was thinking of splitting the 48'' side into two logical 24'' parts, centering the woofer in one side and the ports in the other side. According to the dayton ultimax specs:
"The largest recommended cabinet is 10.5 cubic feet tuned to 16 Hz using two 4" diameter ports that are 21" long for an f3 of 19 Hz."
So, I have two options. I can tune the ports to 16Hz and go 21'' long, however, there will be <2'' between the port and the side of the enclosure since they are going in the 24'' deep part. Will that small of a space cause problems with port velocity? If so, i can tune it to 17Hz and go with 18.3'' long ports, though i'm sure i'd increase my f3 at that point.
also, with a plate amp, there is going to be a high pass filter, typically around 20hz. some of them can be modified. some cannot. I'm not sure about the plate that you mention.
I could not find any definitive answer on the inter-webs for this so i email parts-express tech. Here's their response:
The Rumble filter is set ay 18 hz on this amplifier. For any use under 20 hz I would certainly go with a pro audio amplifier. They have a bit more headroom, and no filtering at all.
So my plan now is to use a Crown XLS 1500 with the voice coils wired in series. That will give me 1550W @ 4ohm which is perfect since the driver peaks out at 1600W. If anyone is aware of issues with this pairing please speak up! With this driver being so new it's hard to find a lot of builds using it.