You wil get BBC HD and ITV HD.
(if you can currently get BBC Channel Islands, then you wil be able ot receive BBC HD - they share a frequency)
You will not get Fiver, Five USA, or C4 HD - these require a sky card.
Your reception of FIVE will be the same reception as BBC2.
YOur regions for 101 and 103 are determined by the postcode you input intot he receiver on installation.
Many channels (Sky news for example) are not available on the Freesat EPG - so you will have to scan for them in non-freesat mode.
(similar to the sky boxes "other channels" option)
look at joinfreesat.co.uk and on the right hand sode of the screen is a list of receivers and the best places with the cheape3st prices (and web discounts)