What type of connection are you looking to get from the MCE to the TFT?? I assume it will be DVI which you can do over CAT5, there are various baluns available however you will need to also consider IR control and audio.
The sky signal can be fed via RF back into a mixer/Amp in the loft and then fed down to the MCE which can then tune in the RF channel along with everything else.
Hope this helps.
Tom