Just saw this kit. Looks interesting and only 59 Euro + Shipment.
_http://www.hm-sat-shop.de/receiver-digital-dreambox/dreambox-dm-70xx-dvd-kit.html
The shipment cost is high, so perhaps this is available in the UK at cheaper shipment.
It looks like the DVD drive sticks out of the box after changing the panel.
Edit: Not good for the 7025S unfortunately because of the large S tuner. But OK for C and T since they have smaller tuners.