do you have the tv already?
if so, do you have the following menu items available?
Turn on your TV
On the TV go to Settings > Network > Home network setup > Remote device/Renderer > On
On the TV go to Settings > Network > Home network setup > IP Control > Authentication > Normal and Pre-Shared Key
On the TV go to Settings > Network > Home network setup > Remote device/Renderer > Enter Pre-Shared Key > 1111 (or whatever you want your PSK Key to be)
On the TV go to Settings > Network > Home network setup > Remote device/Renderer > Simple IP Control > On
thats how I setup all my sony tv's with c4. (do all that first, then have your dealer import the sony ip tv driver and associate).
according to the web manual for the tv it does have ip control that can be turned on.
if it were me, I would take the chance, but just buy it from a place that you can return it from easily, even if its open-box