Hi Surfgeek. I'm using a Fortec Star Passion HD also bought from Maplins. The Fortec will certainly let you watch all the channels you can see with a Freesat box (not a Sky Freesat box). What you don't get is the Freesat 7 day EPG.
The signal strength of 63% sounds a bit on the low side. Mine reads 95% on both the dish that was supplied with the Fortec and on an old Sky dish which I have fixed on Astra at 28. But if a proper installer put the dish in I guess it's OK.
Have you tried a re-scan? The channel list pre-loaded in the Fortec may be out of date.
You could also try an upgrade to the latest loader and then firmware which is available from the Fortec web site.
http://www.fortecstar.com/
Paul