I would connect optical lead from sky+ to opt in sat(remember to select digital sound in sky setup), Hdmi lead from Hdmi out to TV, Hdmi lead from PS3 to tv and optical lead from PS3 to opt video2, Wii component lead to tv and audio L/R to audio in video1. TV audio out L/R to audio in tv. I think this is right! (looking at manuals)
So you need 2x hdmi leads 2x optical leads 1x Wii component lead and 1x rca audio lead. Then you will have spagetti junction behind your tv as I do!

Best purchases are what you can afford! Not uber cheap not uber expensive!