Firstly I would say both the S360 and S760 are fine blu ray players.
Secondly, the price you've quoted sounds a little steep - for example you can get them at RS for
£120 and
£299 respectively, OK it's without any blu ray disks - but you can get these for about £10 if you shop around...
Thirdly the big differences between the S360 and the S760 is the m/c audio out and improved video/audio components. You only need the former if you've got an amp that doesn't take HDMI (like mine doesn't) and the latter gets to be a matter of personal taste; though if you've got a big screen (>=40") or projector you will probably see the difference.
The 3D enabled or enablable (?) sony BDPs come out later in the year, the S770 is rumoured to be about £250-300, similar specs to S760 but with faster load times and 3D...