According to the measurements this layout should work! The sofa is a bit tight, but it fits. I had to move your desk over to the smaller window though, so no more watching the bike riders ;) I kept your paint color the same to keep it easy. And I think you should paint your shelf black to match the rest of your office furniture. Thanks for letting me go over the budget a bit. I wanted to make sure you had a quality sofa bed for your guests.
TOTAL$1,990
Throw Pillows $120
Links Throw Pillows (2) $64
Table Lamp $40
Floor Lamp $60
Art I $28
Art II $28
Grey Velvet 84-inch Blackout Curtain (4) $280
Buchanan Sofa in Gray Twill $1,300