If you are getting an 1842 Springfield, you may want to get an 1842 .69 cal. The gun you want to get is the .69 model 1842 Springfield Musket. Remeber, the '42 is what the 69th was issued. Now for the tents. Each soldier was issued half a dog tent, that they shared with another soldier.
Some reenactors just sleep under the stars.
Or you could buy both halves. You could get a knapsack to pack your things in, but it is not important. There are over coats, the soldiers would wear these in the winter cold. Union Sack coat. Trousers, Sky Blue Cotten Shirt, Suspenders, Wool Socks, Haversack, Canteen, Dark Blue cover, smoothside.