Here's a list of the channels that you'll still be able to receive.
http://en.wikipedia.org/wiki/List_of_free-to-air_channels_at_28%C2%B0E
That's basically the same as Freesat (but without the programme guide or 'red button' services). You should not that UKTV's free channels (such as Dave, Yesterday and Drama) are NOT included in that list, whereas almost all other (terrestrial) Freeview channels are.
You won't be able to use your Sky box to record programmes. You could simply buy
any suitable recording device (such as a PVR or DVD recorder) and feed the output from the Sky box to that. However it's not a perfect solution because you'd have to set the programme on your Sky box but the timings on the recorder. Further, you wouldn't be able to record one programme while watching another. A far better solution would be to purchase a Freesat+ box.