The Remote Sender that you need for a Pace DiTV1000 STB is the AEI Digieye, available from Index stores- product code 551-541.
If you wish to avoid using a coaxial cable for the TV signal, then the AEI DRG 400 Digisender Gold x4 (Index product code 551-540) can transmit the TV signal to a supplied receiver that also transmits the IrDA remote control codes back to the STB.Other equipment such as a VCR or DVD player can also be connected.
Additional receivers can also be obtained -Index product code-551-535.
The AEI DRG 400 Digisenders are also available from Argos and Maplin stores.
http://www.digisender.net