Yes and no.
Freesat is a Platform ie Its branded Receivers collect a 7 day EPG etc. similar to the way Sky boxes do, and allocated fixed Channel numbers etc. and are simply installed by entering a UK Postcode.
The Darty box is a generic Satellite Receiver and should work fine to actual receive UK Free To Air Channels - but it will require setting up with an up to date Transponder list (or just do an Auto Scan if it has that facility).
Only Now & Next EPG but Channels can be re-ordered, removed etc. at will.
The Skybox F3 you linked to is also a generic Satellite Receiver (albeit with more features than your Darty box) so again will require setting up carefully (It does have Blind Scan, which will help - I have two of those boxes!), but frankly I commend you to have another go with the Darty box.
True Freesat Boxes (ie Purpose made to an approved Platform spec.) can be got easily though: The current range is shown at the right hand side of this page
http://www.joinfreesat.co.uk/
PS: Stayed in Poilhes, a mere few km from Capestang, on hols a few years ago: Nice area ............ but being somewhat South, recent (and future) changes in the Satellites used for UK TV will mean it's likely bigger dishes than before will be needed to maintain robust reception)