Loopy,
I'm in the market for a new screen room too so your thread caught my attention.
I've seen plenty of tents that COME WITH a screen room attached as part of a tent but not an add-on to a separate tent. I guess the tent you have your heart set on with the electrical port and ac ports isn't available with a screen room. I've seen tent attachments for the backs of Suburbans and pick-ups but those aren't screen rooms.
What time of year are you planning to be at the Fort? Bugs aren't too bad but if you're there mid-October onward you should be okay. The Fort sprays year round but I'm sure during the warmer humid months there are still some bugs around.
I'm going camping in South Florida after Christmas and want a screen room to protect from the no-seeums that are out at dusk that time of year. I'm in a pop-up so there isn't much room inside and truth be told I'd rather be outside to start with.
Good luck in your search.
Bama Ed