Hi
There are no Freesat PVRs at present but Humax have promised one later this year (HDR-9300FS), hopefully July. I would wait for this.
Your Bush PVR may be able to record SD from the Scart, but HD is not possible.
there is only one HD channel on Freesat at the moment, so if you must have freesat now, get a cheap SD box and wait for the HDR-9300FS. You could then use the SD box in another room.
The HDR-9300FS wil possibly have dual tuners each requiring a seperate feed from the dish. Your SD box will need another, so get a Quad LNB.
Regards