Consider a tent one person larger. If it is going to be two people get a 3 person tent. You will be suprised how fast space is taken up by you gear. REI is a good place to buy a tent.
And practice before going to the Fort!!!
Try to set up camp a couple of times to get use to do it!!! We went to the fort last year (best trip ever!) and took the 3 kids and the camping equipment on the plane with us, arrived at the fort around 1 in the morning so....we were very happy that we were use to set up the tent and it went fast. Also, if you plan to arrive late (or leave very early!) , a flash light that can go on your head or around your neck is very usefull because you see every thing and your hands are still free (sorry, i dont know the right word for that type of flash light...).
I wish you a wonderfull trip!