so you have the TV already.... but have you bought (or been given) the freeview box already?
there are some models that will output via RF, but as mentioned below - they're few and far between... and often more expensive.
there are some very compact SCART to RF modulators - look around the classifieds or on eBay to pick up a cheap 2nd hand one... more and more people are getting rid of these.
again - as mentioned below, if you don't mind the space it takes up and if you already ave an old VCR (that takes SCART IN), then this will perform very well as an RF modulator.
all depends on what you have already (Freeview box and/or VCR?) and how compact the solution needs to be...