chico, that cat tree is magnificent!!
JKC27 - you can make a very simple and good scratch post by using sisal, like on chico's pic, and wrapping it very tighly around a piece of thin plywood - about 5 inches wide and 3 feet tall. Then you can bolt it into the wall, and make another to put elsewhere. Cats really love to scratch this stuff!
And for the nail clipping, don't attempt this in the middle of your cat's play session. Wait until he is deeply asleep and gently start with one paw. If he objects, leave the rest until another day! I clip my cats' nails when they are curled up on my lap.