If you are going to the optical digital route you could go for this -
http://www.amazon.co.uk/Panasonic-SC.../ref=de_a_smtd - which has two optical digital inputs.
What you really need is a unit with more HDMI inputs. I have found this Sony set up -
http://www.currys.co.uk/gbuk/sony-ht...u-ray~05037907 - which has 3 inputs, but obviously doesn't have a Blu-Ray player included. This would enable you to set up all 3 (TiVo, Blu-Ray and PS3) to the HDMI inpits with just the one cable going off to the TV.
I think that at below this price point you may struggle to find units with the inputs you need.