First, I would get solar shades for the windows. I believe justblinds.com or the local blind chain will carry/make them to order. They are considerably cheaper than they used to be and will not void a warranty.
Next, dying the couch contact Joanne at colorplus.
Color-Plus : Interior Leather Care, Coloring, Repair and Restoration for the Auto Enthusiast
She can match to sample or pick one of her ready to go dyes. The cost for the dye is around $150 w/freight or less depending on the quantity and color you need. She has a pricing schedule on her web. Very reliable and usually gets to about a 99.99 % match. She provides dyes to most of the vehicle leather projects I know about around here through a variety of restoration folks and PCA concours types. She is also a wealth of info when restoring leather. That sofa is at half life once you dye it and condition it. The dye results are amazing! It will look brand new, but with the wrinkles, those you really can't do much about although she sells a filler for the really awful cracks.
Good luck